image from http://www.slashgear.com
I wrote this note on the blog, because after the last firmware update the gps 50,005 offline on my nokia 5800xp stopped working: it could not find the satellite!
The problem is this: I had all the settings to use GPS navigator offline, the phone could no longer do the fix the satellite, I initially I found some information here:
http://discussions.europe.nokia.com/t5/Software-Updates/GPS-broken-5800-upgraded-to-50-005/mp/684693
… But it was not enough! I found some people saying that the gps nokia has problems in general to fix the satellite because it is not a real GPS and it should work well only in assisted mode ( A-GPS).
However this thing is not entirely true with the previous version of firmware on my nokia 5800 could do the fix with the GPS satellites quickly without the help of A-GPS! 
I eventually solved by making the first connection to the satellites using A-GPS (assisted online mode). After the first connection (download 480Kb of data it -> maybe update some information on the satellites) the GPS works quite well in offline currently to do the fix the satellite it takes less than 10 seconds!
So even if your GPS after a firmware upgrade does not work the first thing to try is connect via A-GPS online.When you do this procedure you must position yourself OUTSIDE (not at home) and possibly with clear skies and calm (the clouds could disrupt the signal!).
Good luck! 
if not work either mode A-GPS, please contact a service center.
ps
so I can finally use the application SportTracker (this application will speak later).
