Apple fixed the bug reported for Snow Leopard that was causing POSIM to shut down when the keyboard locking issue occurred. If you upgrade to 10.6.2 you will no longer crash if the keyboard lock happens. Instead it will be similar to Leopard where it will lock until you click off the screen and back on.
If you never had the keyboard locking issues in Leopard there is still no evidence that suggests you will have the issue in Snow Leopard. If you would like more information about this you can find a tech note here.
There has also been an issue with Snow Leopard and Controller (multi site), which is in review and should be fixed shortly. Wait for the fix before upgrading.
If you have any questions about upgrading your OS and the impact on POS•IM, please contact tech support and they can assist you.
