2.0 Install problem

[Coastie]

Installed 2.0. Firefox and Thunderbird would not start because they were said to be running. Rebooted as instructed. Still the would not start. uninstalled  both completely and installed Chrome and tried to import .mozilla from backup file to see if I could get bookmarks. Chrome said Firefox was running even though uninstalled. Reinstalled Firefox and Thunderbird without using backup .mozilla and still said they were running. Tried to open Firefox from install dvd but still said were already open. I think they may have run on installation or dvd before I replaced .mozilla and .thunderbird.

Reinstalled previous OS and everything works.

Is this fixable so I can run LL 2.0?