I am currently using firefox and having trouble installing new addons. The problem didn't occur before Firefox updated to the new 2007 version.
Whenever i try to install, an error message pops up:


Firefox could not install the file at:

http://addons.mozilla.org............

because: Unexpected installation error.


I would really appreciate it if someone could help me with this. Its an awesome website!

i fixed the problem, thanks to a helpful post on the firefox forums.

the solution is as follows:

Problem: My extensions have gone or are unusable....
The update has confused the extension manager.... This procedure will reset it, so Firefox rescans your collection of addons, to see what is really there.

Solution:Look in your Profile Folder (see above for how to find it) and Delete these three files
extensions.ini
extensions.cache
extensions.rdf
Make sure Firefox is not running when deleting these files. Firefox will regenerate these files on restart.