I'm using Avast 6.0.1000 Free with ST 2.8.2.192 on Vista Home Basic SP2 and have no incompatibility problems.
In fact, I said that in another my O.S. (Windows 7, I mean), I haven't had no problems.
Only with Windows XP I encountered this kind of error. I don't know why.
I am not sure what program is guilty in your case but I would like you not to hurry and accuse ST.
I don't know, too.
I think ST is a good software (I installed it in all my computers), as Avast is one of the best antivirus.
I would like so much they could collaborate ...
If someone with a configuration like mine could check this situation ...
I've a virtual machine with Windows XP Professional (update till SP3), as I said, but with no internet connection. In this case I don't have any problems!
As soon as possible I'll try once again with my virtual machine, manual updating ST ...
For instance, thank you all!!!