Wladimir Palant wrote:guest04, this usually helps: http://kb.mozillazine.org/Unable_to_ins ... sion_files
I've tried even removing my profile and starting over, with no success. I've been researching this problem for some time before coming here; the closest I can find to a positive result is documented at http://cnx.com/?p=1183 but that didn't work for me, either.
With Adblock Plus installed, I get a resizable (but empty) frame at the bottom of the Firefox window. I don't get an Adblock Plus icon in the upper-right. Eventually, my Firefox Tools dropdown menu turns to mush, and has a positively huge amount of whitespace -- so much so that I can't even get to the Tools -> Add-ons menu without starting Firefox in safe mode. The right-click context menu turns to goop, too. And ctrl-refresh, instead of refreshing the cache, quietly opens the current URL in a new tab.
Yes, things here are very broken. I'd been using Adblock Plus for years. At some unmemorable point, I noticed how broken it was. I searched, I dug, I uninstalled a bunch of add-ons (keeping ABP, of course), and then in desperation nuked my profile and started over clean (except for my bookmarks, which I exported and reimported afterward). I then carefully installed my add-ons, one by one, and it's very plain to me that this behavior begins as soon as ABP is installed, and that everything is fine as soon as ABP is removed.
System is Vista Business x64. Have tried ABP 1.1, and the latest development build. Have tried FF 3.5beta4, FF 3.5.1, and FF 3.5.2, all of which were standard 32-bit builds from the Firefox web site.