Few points what peoples tend to forget, when they use this miraculous GPS technology with Sirf III synonym in their minds. So, when powering GPS up, it's important to understand few facts which really help GPS receiver to perform well and produce valid fix;

1. GPS needs to get clear view to sky (handheld device is always in secondary role, when compared to bluetooth devices, which can be put far front in car).

2. This view should no be blocked by moving GPS receiver around, or wondering by yourself in view of satellites. Some window material is also very efficient to block these GPS signals. This becomes an issue, when GPS is used with old ephemerides data, since downloading ephes from satellites takes continuous, non interrupted flow of GPS information frames, each 30 s long. This is typical 'fast guy' syndrome, when user looks at display of device for few seconds and while it seems that nothing is happening, he takes devices and shakes it (at least) while wondering why Nokia crap is not working.

3. Keep receiver still. Driving and wondering around keeps blocking that very important phase of ephe downloading and it's very likely that it will never succeed.

4. When you have spent over 4 hours (or so) without GPS on, you have to understand that satellites in view and old ephes are non valid for warm start. Keep this in mind.