At Andy's suggestion, I called this problem into support. Not for the faint of heart, but the critical restore that I needed to get done today has now completed.
This only affects WinNT and Win2K clients and the problem is the server, not the client. Support says that it will be fixed in the next release, whether or not that is v4.2.2.x or v.5.1.x.x, he didn't know. A unicode 'thing'. Thanks for everyone's responses. Gretchen Thiele Princeton University