I had some major issues moving from v5 to v6 - after
countless tries (uninstalls / installs, registry edits, offerings
to the gods, etc.), I gave up and reverted back to 5. Then, when I
got 7, it didn't want to cooperate either. There are some threads
of discussion I took part in about this, but they are to painful to
dig up and relive!
Very long story short, I ended up rebuilding the CPD file in
v5 BEFORE running the upgrade against my projects, then installed
v7. Even now, I occasionally have to rebuild the CPD, when it gets
bloated. But doing the initial repairs in v5 was the solution.
And this is without the whole SourceSafe layer to contend
with.
I feel your pain.