A failure of ashquick.exe was reported to me by another avast user (4.6.744 with WinXP SP2). The failure was apparently intermittent but repeatable on scanning a particular file downloaded from Microsoft.
The ashquick scan gave the normal two windows one showing the scan and the other the final statistics of the scan and then the XP error window appears with:
aswQuick Module has encountered a problem and needs to close
Highlighting by me to stress change in module name reported.
Since I could not immediately repeat the problem I advised the user to run the Repair function for avast but the error could still be reproduced following the repair.
I have now been able to reproduce the same error scanning the same file on my system.
I have the dump available if the avast team care to review it.
It has nothing to do with loading definitions, the problem occurs after scanning several files in the preceeding seconds - and the problem can be repeated on two different systems.