In my winapp2.ini I coded the following for Antivir version 10 (not sure about v8 or v9 though)
[*AntiVir Personal 10]
; Removes only the safe to remove files .tmp and .log!
LangSecRef=3024
Detect=HKLM\SOFTWARE\Avira\AntiVir Desktop
Default=True
FileKey1=%commonappdata%\Avira\AntiVir Desktop\BACKUP\FAILSAFE|*.tmp
FileKey2=%commonappdata%\Avira\AntiVir Desktop\LOGFILES|Upd*.log
FileKey3=%commonappdata%\Avira\AntiVir Desktop\LOGFILES|AVSCAN*.log
FileKey4=%ProgramFiles%\Avira\AntiVir Desktop|*.tmp
FileKey5=%ProgramFiles%\Avira\AntiVir Desktop\FAILSAFE|*.tmp
I left the logfiles avguard, sched and setup alone in case the program does not recreate them.