I'd gotten to the point that I got regular GPS fixes. After an OS upgrade my ability to get GPS fixes in any reasonable time disapeared. I tried all the tricks I documents in http://FragosTech.com/MaemoMapper and still no cigar. The answer to my problem was to run AGPS. Apparently when the OS was upgraded the AGPS daemon wasn't restarted. Now everything is back to as good as the N810 GPS can manage.

I found that one of the recent updates to AGPS prevented me from getting a fix until I had rebooted the device. THen all was well. Worth knowing if MAP or AGPS updates are done separately to an OS upgrade which will presumably always result in a reboot.