OnAccess-Scanner freezes system every few seconds

[AllesMeins]

I installed Avast two days ago. Since then i had to notice a strange behavior. Every few seconds the OnAccess-Scanner freezes my machine for 1-2 seconds (the CPU-Usage jumps to 100% and everything else - including the cursor stops working). Deactivating the scanner fixes the problem, but that isn't a real solution.

Athlon 64 3000+
1024 MB RAM
Win 200 SP4
One 80 GB IDE Harddrive
2x160GB SATA Raid

Any ideas, what might cause this problem?

[Eddy]

Did you or do you have another AV on that system?
If so, that will likely be the culprit.
Make sure it is removed completely before installing avast!

[alanrf]

Do you have Thunderbird running as your mail client when these "freezes" happen?

You can also check the name of the last file scanned in the Standard Shield and see if the same file name is there when the freeze occurs.  Some folks have experienced issues with large logging files being frequently accessed.

[AllesMeins]

No, I've no other "security"-software running. No firewall, no anti-virus. I deinstalled my old anti-virus program before installing avast, and as far as i can tell it was removed completely.

I'm using Seamonkey-Mail, so it might be pretty close to thunderbird. I'm not sure, if the freezing only occurs, when seamonkey is running.

[alanrf]

Assuming SeaMonkey is similar to Thunderbird then to make sure it is not involved it would be a good idea to check that your trash folders are emptied and that all the mail folders have been compacted to really remove deleted messages.

Have you noticed which process is recording the high CPU utiliztion in the Task Manager? 

When you mention the OnAccess scanner I am guessing you are talking about turning off all OnAcess protection. Have you tried turning off the individual providers in avast to see if you can identify one that, when turned off, stops the freezes?

[Eddy]

What other av was on the system?
If it was Norton, use the search option on this board to find out how to really remove everything from it.
The add/remove in control panel will leave many things behind.

[AllesMeins]

I think i found the reason. It seems to be the "Instant-Messaging-Scanner" scanning an 8MB Trillian XML-Logfile. Strange thing is, i can open, edit and save far bigger files without Avast! freezing my system. Why does it make such a difference, when the IM-Scanner checks the file instad of the "normal" scanner, when opening the file the "normal" way?
Any idea how to handle this problem without deleting the corresponding logfile?

[DavidR]

You could add it to the exclusions lists, Standard Shield, Customize, Advanced and Program Settings, Exclusions.

[stageman]

Assuming SeaMonkey is similar to Thunderbird then to make sure it is not involved it would be a good idea to check that your trash folders are emptied and that all the mail folders have been compacted to really remove deleted messages.

Have you noticed which process is recording the high CPU utiliztion in the Task Manager? 

When you mention the OnAccess scanner I am guessing you are talking about turning off all OnAcess protection. Have you tried turning off the individual providers in avast to see if you can identify one that, when turned off, stops the freezes?

I am having the same issues. My computer freezes/pauses everytime I download or open a message with Thunderbird. I've compacted my mail boxes and that hasn't helped at all. The freeze problem is especially bad with downloading my gmail to a local folder.

System info:
Intel Centrino 2.0Ghz
1GB RAM
Windows XP Pro SP2