Forms positioning behavior. Bug?

I've got a Progress window (.w) & a .Net form (.cls). Both very simple. I open the cls from the .w. No problems so far.

Now, when I click on the .w, my .Net form gets positioned behind the procedure editor (or application menu). It should be positioned behind the .w. The second time I launch the .w in the same session, the .Net form gets indeed positioned behind the .w

Does anybody why this happens? Basically it means in our full application (classic .W) the .Net form seems to disappear. It's not: it's behind the menu. But you can see this is not user friendly.

Below are the 2 windows (well, form & window). If you run these from a simple prowin32, you'll see what I mean. Hopefully. 

EDIT: I've tested both on 10.2A & 11.3. On 10.2A, it's seems to work correctly

.w:

&ANALYZE-SUSPEND _VERSION-NUMBER AB_v10r12 GUI
&ANALYZE-RESUME
&Scoped-define WINDOW-NAME C-Win
&ANALYZE-SUSPEND _UIB-CODE-BLOCK _CUSTOM _DEFINITIONS C-Win

CREATE WIDGET-POOL.

/* *************************** Definitions ************************** */

/* Parameters Definitions --- */

/* Local Variable Definitions --- */
def var frm as class testform no-undo.

/* _UIB-CODE-BLOCK-END */
&ANALYZE-RESUME

&ANALYZE-SUSPEND _UIB-PREPROCESSOR-BLOCK

/* ******************** Preprocessor Definitions ******************** */

&Scoped-define PROCEDURE-TYPE Window
&Scoped-define DB-AWARE no

/* Name of designated FRAME-NAME and/or first browse and/or first query */
&Scoped-define FRAME-NAME DEFAULT-FRAME

/* Standard List Definitions */
&Scoped-Define ENABLED-OBJECTS BUTTON-1
&Scoped-Define DISPLAYED-OBJECTS 
/* Custom List Definitions */
/* List-1,List-2,List-3,List-4,List-5,List-6 */

/* _UIB-PREPROCESSOR-BLOCK-END */
&ANALYZE-RESUME

/* *********************** Control Definitions ********************** */

/* Define the widget handle for the window */
DEFINE VAR C-Win AS WIDGET-HANDLE NO-UNDO.

/* Definitions of the field level widgets */
DEFINE BUTTON BUTTON-1 
 LABEL "Button 1" 
 SIZE 15 BY 1.14.

/* ************************ Frame Definitions *********************** */

DEFINE FRAME DEFAULT-FRAME
 BUTTON-1 AT ROW 2.43 COL 9 WIDGET-ID 2
 WITH 1 DOWN NO-BOX KEEP-TAB-ORDER OVERLAY 
 SIDE-LABELS NO-UNDERLINE THREE-D 
 AT COL 1 ROW 1
 SIZE 80 BY 16 WIDGET-ID 100.

/* *********************** Procedure Settings ************************ */

&ANALYZE-SUSPEND _PROCEDURE-SETTINGS
/* Settings for THIS-PROCEDURE
 Type: Window
 Allow: Basic,Browse,DB-Fields,Window,Query
 Other Settings: COMPILE
 */
&ANALYZE-RESUME _END-PROCEDURE-SETTINGS

/* ************************* Create Window ************************** */

&ANALYZE-SUSPEND _CREATE-WINDOW
IF SESSION:DISPLAY-TYPE = "GUI":U THEN
 CREATE WINDOW C-Win ASSIGN
 HIDDEN = YES
 TITLE = "<insert window title>"
 HEIGHT = 16
 WIDTH = 80
 MAX-HEIGHT = 16
 MAX-WIDTH = 80
 VIRTUAL-HEIGHT = 16
 VIRTUAL-WIDTH = 80
 RESIZE = yes
 SCROLL-BARS = no
 STATUS-AREA = no
 BGCOLOR = ?
 FGCOLOR = ?
 KEEP-FRAME-Z-ORDER = yes
 THREE-D = yes
 MESSAGE-AREA = no
 SENSITIVE = yes.
ELSE {&WINDOW-NAME} = CURRENT-WINDOW.
/* END WINDOW DEFINITION */
&ANALYZE-RESUME

/* *********** Runtime Attributes and AppBuilder Settings *********** */

&ANALYZE-SUSPEND _RUN-TIME-ATTRIBUTES
/* SETTINGS FOR WINDOW C-Win
 VISIBLE,,RUN-PERSISTENT */
/* SETTINGS FOR FRAME DEFAULT-FRAME
 FRAME-NAME */
IF SESSION:DISPLAY-TYPE = "GUI":U AND VALID-HANDLE(C-Win)
THEN C-Win:HIDDEN = no.

/* _RUN-TIME-ATTRIBUTES-END */
&ANALYZE-RESUME

/* ************************ Control Triggers ************************ */

&Scoped-define SELF-NAME C-Win
&ANALYZE-SUSPEND _UIB-CODE-BLOCK _CONTROL C-Win C-Win
ON END-ERROR OF C-Win /* <insert window title> */
OR ENDKEY OF {&WINDOW-NAME} ANYWHERE DO:
 /* This case occurs when the user presses the "Esc" key.
 In a persistently run window, just ignore this. If we did not, the
 application would exit. */
 IF THIS-PROCEDURE:PERSISTENT THEN RETURN NO-APPLY.
END.

/* _UIB-CODE-BLOCK-END */
&ANALYZE-RESUME

&ANALYZE-SUSPEND _UIB-CODE-BLOCK _CONTROL C-Win C-Win
ON WINDOW-CLOSE OF C-Win /* <insert window title> */
DO:
 /* This event will close the window and terminate the procedure. */
 APPLY "CLOSE":U TO THIS-PROCEDURE.
 RETURN NO-APPLY.
END.

/* _UIB-CODE-BLOCK-END */
&ANALYZE-RESUME

&Scoped-define SELF-NAME BUTTON-1
&ANALYZE-SUSPEND _UIB-CODE-BLOCK _CONTROL BUTTON-1 C-Win
ON CHOOSE OF BUTTON-1 IN FRAME DEFAULT-FRAME /* Button 1 */
DO: 
 frm:show().
END.

/* _UIB-CODE-BLOCK-END */
&ANALYZE-RESUME

&UNDEFINE SELF-NAME

&ANALYZE-SUSPEND _UIB-CODE-BLOCK _CUSTOM _MAIN-BLOCK C-Win

/* *************************** Main Block *************************** */

/* Set CURRENT-WINDOW: this will parent dialog-boxes and frames. */
ASSIGN CURRENT-WINDOW = {&WINDOW-NAME} 
 THIS-PROCEDURE:CURRENT-WINDOW = {&WINDOW-NAME}.

/* The CLOSE event can be used from inside or outside the procedure to */
/* terminate it. */
ON CLOSE OF THIS-PROCEDURE 
 RUN disable_UI.

/* Best default for GUI applications is... */
PAUSE 0 BEFORE-HIDE.

/* Now enable the interface and wait for the exit condition. */
/* (NOTE: handle ERROR and END-KEY so cleanup code will always fire. */
MAIN-BLOCK:
DO ON ERROR UNDO MAIN-BLOCK, LEAVE MAIN-BLOCK
 ON END-KEY UNDO MAIN-BLOCK, LEAVE MAIN-BLOCK:
 RUN enable_UI.
 
 frm = new testform().
 frm:ProWinHandle:parent = CURRENT-WINDOW.
 WAIT-FOR System.Windows.Forms.Application:Run().
 System.Windows.Forms.Application:Exit().

END.

/* _UIB-CODE-BLOCK-END */
&ANALYZE-RESUME

/* ********************** Internal Procedures *********************** */

&ANALYZE-SUSPEND _UIB-CODE-BLOCK _PROCEDURE disable_UI C-Win _DEFAULT-DISABLE
PROCEDURE disable_UI :
/*------------------------------------------------------------------------------
 Purpose: DISABLE the User Interface
 Parameters: <none>
 Notes: Here we clean-up the user-interface by deleting
 dynamic widgets we have created and/or hide 
 frames. This procedure is usually called when
 we are ready to "clean-up" after running.
------------------------------------------------------------------------------*/
 /* Delete the WINDOW we created */
 IF SESSION:DISPLAY-TYPE = "GUI":U AND VALID-HANDLE(C-Win)
 THEN DELETE WIDGET C-Win.
 IF THIS-PROCEDURE:PERSISTENT THEN DELETE PROCEDURE THIS-PROCEDURE.
 quit.
END PROCEDURE.

/* _UIB-CODE-BLOCK-END */
&ANALYZE-RESUME

&ANALYZE-SUSPEND _UIB-CODE-BLOCK _PROCEDURE enable_UI C-Win _DEFAULT-ENABLE
PROCEDURE enable_UI :
/*------------------------------------------------------------------------------
 Purpose: ENABLE the User Interface
 Parameters: <none>
 Notes: Here we display/view/enable the widgets in the
 user-interface. In addition, OPEN all queries
 associated with each FRAME and BROWSE.
 These statements here are based on the "Other 
 Settings" section of the widget Property Sheets.
------------------------------------------------------------------------------*/
 ENABLE BUTTON-1
 WITH FRAME DEFAULT-FRAME IN WINDOW C-Win.
 {&OPEN-BROWSERS-IN-QUERY-DEFAULT-FRAME}
 VIEW C-Win.
END PROCEDURE.

/* _UIB-CODE-BLOCK-END */
&ANALYZE-RESUME

.cls:

USING Progress.Lang.*.
USING Progress.Windows.Form.

ROUTINE-LEVEL ON ERROR UNDO, THROW.

CLASS testform INHERITS Form: 
 
 DEFINE PRIVATE VARIABLE components AS System.ComponentModel.IContainer NO-UNDO.

 CONSTRUCTOR PUBLIC testform ( ):
 
 
 SUPER().
 InitializeComponent().
 /*THIS-OBJECT:ComponentsCollection:ADD(THIS-OBJECT:components).*/
 CATCH e AS Progress.Lang.Error:
 UNDO, THROW e.
 END CATCH.

END CONSTRUCTOR.

METHOD PRIVATE VOID InitializeComponent( ):
 
 /* NOTE: The following method is automatically generated.
 
 We strongly suggest that the contents of this method only be modified using the
 Visual Designer to avoid any incompatible modifications.
 
 Modifying the contents of this method using a code editor will invalidate any support for this file. */
 THIS-OBJECT:SuspendLayout().
 THIS-OBJECT:Name = "testform".
 THIS-OBJECT:Text = "testform".
 THIS-OBJECT:ResumeLayout(FALSE).
 CATCH e AS Progress.Lang.Error:
 UNDO, THROW e.
 END CATCH.

END METHOD.

DESTRUCTOR PUBLIC testform ( ):

END DESTRUCTOR.

END CLASS.