-SOLVED-
The problem was my PRI version. I was at 1.17_003 and needed to get to 1.18_003.
The solution was found on this forum at:
http://forum.ppcgeeks.com/showthread...ternet+roaming
I don't know how I missed that, but if anyone else runs into this, there you go...
I think what happened is that I went right from the "out of the box" ROM to WM6, skipping the intermediate OEM ROMs (which would have updated my PRI).
Anyhow, thanks all,
Tomn8tr.