Ok, just tried it with both supl.google.com and supl.google.com:7276.
Definitely seems to lock quicker than with the Nokia server, but may have had a cached GPS location anyway.
Unfortunately, doesn't make any difference to the widget.
It has worked very occasionally in the past (when I first got the phone) then stopped altogether. Thought I'd try it out again after PR1.2, but no joy.