I just recently discovered that I had problems with Firefox showing the “Write”, “Manage” and “Comments” pages within the WordPress interface. It took much too long time to display the pages after clicking on the link. IE worked fine, though.

So, I thought about what changes I’ve made recently, and I recalled installing Kaspersky Antivirus 6 lately. One of the KAV modules is the “Web-Anti-Virus” that is supposed to scan http-headers while surfing. It was set to “recommended” by default.

After setting it to “low”, everything worked fine again.

I don’t really know if there is a close connection, but I have read several threads in the Kaspersky forum referring to firefox.

I am still using the trial version, and I am not sure wether to buy Kaspersky AV if this problem remains. Actually, I toy with the idea of maybe switching to Avira AntiVir PersonalEdition Premium. I used the classic version before and had no problems, but I am missing a POP3 scanner there, which the premium edition includes.

[Update from 2007-03-12]
It seems that Kaspersky Web AV has also problems playing videos from Youtube.com with Firefox. I have disabled that Web AV feature for now. Guess I’ll try AntiVir next…