Sitefinity CPU pegging at 99% in production

Hello,

 Is anyone else having this problem?  We have several production Sitefinity installations and ever since we wen't to 6.0 we've encountered the following problem.

 At random times Sitefinity will go into some sort of state and the CPU will jump to 99%.  Worse it will start to gobble up all the available memory.  At one point it was up to 4 gigs before the we killed the process.

We haven't introduced any code into our installation is a long time and the code that we do have is very minor in nature.  Not the sort of code that would generate such a drastic memory leak.

 Is anyone else having this issue? 

 Pierre