If I under stand you right
4.1 -> 4.2 possible
4.1 SP 1 -> 4.2 NOT possible
4.1 SP 2 -> 4.2 possible
4.1 SP 3 -> 4.2 possible
It just strikes you odd that 4.1 without an service pack is supported to be upgraded to 4.2. But if you have an officel SP1 installed you first need to upgrade to SP2 before going to 4.2.
SP2 was so bad that it never was usable. Thats why I skipped it and waited for 4.2
So your 'you can' simply means 'you have to'. Twice the work. I would have expected that all versions can 4.1 can be updated to 4.2 especially if you upgarded to a service pack.
Strange but who is wondering these days ;-(