Hi Daibus So far as getting 22.214.171.124 back on the system is concerned then you may have to go through the uninstall/reinstall process. So far as getting it all back the way it was before ..... you have probably got problems. Installing version 3 ,while it would run alongside 126.96.36.199,has in fact altered your profile which affects whatever version you are running. Your profile - which is in Documents and Settings/User Name/Application Data/Mozilla is totally independent of the Firefox folder in program files but is altered by alterations which you make to Firefox. You will probably find that you have lost the add-ons which were not compatible with version 3. You should have saved a copy of your profile before trying out version 3 .... it is no consolation but I found out the hard way too.
I should also point out that the Beta versions of Firefox 3 installed themselves into a separate folder in program files so should be able to be installed/uninstalled independently of each other.(but still affecting your profile as I described above) The RC1 version currently available ,in my case anyway, actually overwrote the version 2 installation.
In the end I deleted Firefox from Application Data which then allowed 188.8.131.52 to be installed although without anything from the old Profile folder included.
I had tried to install a previous folder via MozBackup, that I have on my PC, without success but after the latest reinstall a previous folder did manage to install so giving me back all my previous settings in Firefox - voila !