Firefox: extension compatibility

If your favorite extension is not compatible with your Firefox version you can try to block the compatibility check.
When a developer makes an extension he writes the version of Firefox in which he thinks his extension works,
so if a extension is blocked when you install a new version of Firefox doesn't mean it doesn't work.
Maybe if the extension is too old and the browser is too new some problem could happen.

I'm trying to install the Avast extension, but is not compatible with FF5.0... but now it works!

Follow this instruction to block the compatibility check:

•  open Firefox
•  read the version number (Help - Information on Firefox)
•  write in the address bar this:   about:config
•  right click for the menu and select New - Boolean
•  in the textbox write: extensions.checkCompatibility.YOURVERSION  where YOURVERSION is the number obtained reading the Firefox version
• Click Ok and select "False" as boolean value
• restart Firefox

My FF version number is 5.0 so I put :

If you wanna return back search "extension.checkCompatibility...." in the filter textbox in about:config and double-click the voice to put "True" or simply delete the voice.