15 June 08 EDIT: This thread largely irrelevant now, as most FF add-ons updated and now working OK with FF3
If like me you have Firefox extensions that will not work with Firefox 3 Beta4, or you simply don't like FF3 you can replace it with Firefox 2.
First close any Firefox windows then open Synaptic and search for firefox.
Mark firefox-3.0 for complete removal and click apply.
Then in your Home folder, locate the hidden .mozilla folder.
(either by pressing Ctrl+h or View>Show Hidden Files)
Inside the .mozilla folder is the firefox folder.
Move the firefox folder to the trash, then empty the trash..
Next search Synaptic again for firefox and click on the firefox-3.0 line to highlight it, then in the top menu bar click "Package" then select "Lock Version"
This will prevent Firefox 3 from being re-installed.
EDIT: Also completely remove then lock all the other firefox-3 entries and the firefox (metapackage) there are reports that Firefox 3 can reappear unless all the firefox-3 entries are removed and locked.
Next, check that the /home/<username>/.mozilla/firefox folder is still deleted.
Search again for firefox in Synaptic then mark firefox-2 for installation and click apply.
You will now be able to use a much wider range of add-ons and your Home button won't be in the Bookmarks Toolbar. Why was it moved there? Grrr!
EDIT: Home button now back in it's rightful place with Beta5