Home configuration:
Pentium D920, 2GB RAM.
Win XP Pro SP2 Updated.
MS Office 2007 (No SP1)
Visual Studio 2005 (No SP1)
Avast 4.7 Home Edition
Dec2007 (4.7.1098)
Facts:
1 - Yesterday, avast updated the virus definitions (VPS) and since then, Winword hangs when I open one of my old documents (Word 97 format) but works fine with some other documents in Office 2007 format (*.docx).
2 - When this problem occurs, the process ashServ.exe takes SYSTEMATICALLY 50% of my CPU resources (I have a Dual Core).
In other situations, ashServ.exe CPU usage is very low.
3 - If I stop avast resident protection, it has no effect. Winword still hangs. ashServ is still taking one full CPU.
4 - I can not kill WINWORD.exe. Actually, Winword never stop even thought I see the standard windows "Terminate process" "send report to MS" and so on .
5 - If I kill ashServ.exe, everything comes back to normal, except I have no more resident protection :

6 - I reproduce this behaviour systematically on my home PC.
7 - I was also able to reproduce this behaviour on an other machine (An AMD athlon based machine)
8 - This problem does not occur with an older version of Winword (Office 2003) even if avast is running with the last VPS.
9 - This problem does not occur with Winword 2007 if avast is not installed!
I guess this has to do with the last VPS. Don't you think so? ;-)
Regards