Analyzing suspicious program message issue

Every time I open a “pps” file by double clicking the file, I get the Avast message “Avast is analyzing suspicious program…” and offers to sandbox the program. I let it time out and click “Continue execution”.

I have added powerpnt.exe to the list of files that are excluded from autosandboxing.

If I start Powerpoint and then load the pps file, I don’t get this warning.

I always manually scan every downloaded file before executing so I don’t need this auto sandboxing behavior.

How do I stop it?

I’m using version 7.0.1466 of Avast on Windows XP SP3 with all updates.