klaattu,
That error is due to the TDinstaller being ran more than once. Some of the settings fields were probably created before you got the error about the profile fields, thus the duplicate field error.
Try this: If you haven't already done so, restore your database to the state it was prior to running the installer. Login to your admincp and manually remove fields 50-65 in the profile field manager. Just to be sure, use phpmyadmin to make sure that all fields/columns with IDs from 50-65 have been removed from both the profilefield and userfield tables. Now use the instructions for installing v2.1. The installer should now run flawlessly.
If you still can't get it working I'd be happy to set it up for you. Email me at
webmaster@modernmusclecars.net.