User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:184.108.40.206) Gecko/2008091620 Firefox/3.0.2 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:220.127.116.11) Gecko/2008091620 Firefox/3.0.2 All the buttons are greyed. The ininstall button shouldn't be Reproducible: Always Steps to Reproduce: 1. Try to uninstall a disabled add-on 2. 3.
What extensions are you referring to? Can you attach copies of extensions.ini, extensions.rdf, extensions.cache and extensions.log from your profile folder to this bug report http://support.mozilla.com/en-US/kb/Profiles
We can't investigate this further without the information asked for in comment 1