For those doubting they have a gps problem.
Disable network position in the location. Disable Phone.
Install mapper from the app manager Lauch it. Open the GPS information tab.
It shows the amount of satellites in view and their signal. Position your device on something solid when your are (!) OUTSIDE (!).

Just wait. If it's your first time, the phone probably needs from 3 to 5 minuts to get a fix.
That's how a proper GPS works.
And don't whine about iphone Maps. They always use network positioning, and Iphone's gps is crap without GSM/Wifi available. That's why the first iphone without GPS module at all, is also pretty fast in Maps positioning.

The GPS in n900 should be able to make you out in a desert or somewhere between nowhere, where's no cellular coverage. Actually, that's where GPS is usually needed, and not in the range of your home wifi AP.

Still trying to figure out if nokia's n900 chip is inferior to old good sirfstar3.
What's the model of the chip anyway?