Rated 3 out of 5 stars

If you get problems with short cut combinations e.g. web console under firefox 4 using CTRL+SHIFT+K.
Try installing KeyConfig extension from http://mozilla.dorando.at/
Once installed, bring up the Keyconfig options & set "abort element selection" to your preferred combination, locate combination duplicate from list & re-assign or remove.

If you get an add-on that comes up as disabled you can TRY modifying the <em:maxVersion> number in the install.rdf file for this extension

How:
Download the extension to your desktop
open the .xpi file in an archive prog e.g. 7-Zip (associate the file type with prog if needed)
Open install.rdf file in notepad or similar, search file for <!-- firefox -->
Just below there is an entry labelled <em:maxVersion>
Change the number that follows for example <em:maxVersion>5.0.*</em:maxVersion>
Save file & update archive, drag into firefox to install.

This review is for a previous version of the add-on (1.1.1.1-signed).  This user has a previous review of this add-on.