SO far Numernor, Marvine, & I have experienced sims freezing to death in CAS. This has resulting in the game crashing to the desktop. It has occurred in both unedited and edited CAS'es. Whether the CAS was edited in Seasons or not seems to make no difference from what I have seen so far.
If anyone else has experienced this please post it in this thread so we can see if a pattern evoloves.
I have had this problem too, but only with CAS that I made with Seasons installed, just as I got random pets showing up in CAS when I made one with Pets installed.
I havnt had any problems with any CAS made pre-pets or pre-seasons though.
This is what happens with the Pets bug: