Reid - 12:33 am on May 13, 2006 (gmt 0)
are you sure you are using 301 and not 302?
I would double check it with a header-response viewer.
G should have the new or both listed. Maybe there is a stray inbound link somewhere that you missed?
Check your server logs and if both are being requested still by gbot (maybe you will find a referrer page in there) then put a 410 on the old one, this should not affect the new one.