avast update breaking bluetooth

After a recent avast update, I get the following error message after rebooting:

Bluetooth Keyboard and Mouse Recovery: LogonUI.exe - Application Error The exception unknown software exception (0xc000000d) occurred in the application at location 0x100230b7.
I used Acronis TrueImage to restore my complete system to a week ago (5/18/2011). Rebooted, and it was fine. Kept rebooting, still no problems. Then I allowed avast to update and rebooted, and the problem is back.

If I disable avast and reboot, no problem. If I enable avast and reboot: Problem.

All my bluetooth and system drivers and chipset, bios, everything is all up to date. (Using the Dell Client System Update).

I will happily add an exception to avast, if only I know what exception to add… There is no log that I can find anywhere in avast, to indicate what file avast is complaining about. The error message suggests it is not caused by a file, but the actual application running resident in memory. So … How can I get avast to stop causing this problem?