FWIW, I've seen the same behavior on Win2K Pro, with TSM 3.7.2 client.
Restoring the registry gives "unable to restore one or more registry keys",
with no further error message or explanation.

However, in every case, I was able to reboot, then run the registry restore
a second time.  It always worked OK the second time, so I was sure the
registry was (eventually) OK.  Should have reported it, but never got around
to it, since it never caused me a serious problem.