Outlook 2003 - avast incompatibility

Since I tried to install windows fax utility a week ago, I experience problems with my outlook 2003: it freezes every time I change languages when on the calender menu (only!). The only solution is to turn off Avast. I tried uninstalling and reinstalling avast and outlook, tried to enable and disable the plugin mentioned in this forum that appeared in the help menu of outlook 2003, tried to disable the outlook scanning facility in Avast - all with temporary or no effect. Deleting the cookies from ie helps for a short while.

Any idea what I could do to solve the problem?

Which was your old antivirus before avast? How did you uninstall it?
Any other security program that could interfere?
Which is your avast version? And Windows version?

AVG. That was a long time ago. I do not remember the exact uninstall method, but everything worked very well after for many months.
I have Ad- Aware and Spybot and spywareblaster. But again - everything works well when I turn off Avast. An additional detail: when I remove English language, leaving only Hebrew also everything is ok.
Avast version 4.8 home edition. Windows xp professional SP3

AVG Remover can be downloaded here: http://www.avg.com/download-tools
It could “clean” the problem.

Just did that now - in a strange way it looks as if it helped a little bit (???), but so did other measures I took in my trials to troubleshoot the problem: erasing the cookies, reinstalling avast, reinstalling outlook. All those actions initially caused the outlook not to crash. But gradually the situation worsened again. Anyone additional ideas what else can be done?