As far as I’m aware avast doesn’t do that.

Even if it did, I don’t know why it would only block deletion of the Internet Temp Files and not stop other deletions.

I haven’t experienced this on firefox, it is a very, very rare occasion when I use IE8 on this system.

I set the Internet Options to cleat the Temp Internet Files on browser closure. I have just done some browsing using IE8 and checked the Temp Internet Files folder and there was a little over 400KB of files. Closing the browser and doing a check of the Temp Internet Files folder the temp files were gone, some cookies remained and two .ico files.

Now I don’t have cookies deleted using the normal settings (Tools, Delete Browsing History), so that may explain why they weren’t removed. No idea why the .ico files wouldn’t be classed as Temp Internet Files.

So for me it appears to be working.

Are you using the Avast Online Security Add-on ?