Is there a diagnostics or debug utility for the N8x0? If things don't work I'd like to see why.

The built-in applications show four green bars when everything is fine and if not all bars are grey. I cannot really interpret this. The green bars probably stand for visible/used satellites, the height of the bars is probably signal strength. So what do the grey bars mean? (invisible and zero signal?)

I don't fully understand how GPS works, but everyone knows it requires a signal from minimum three satellites and some data (time, know position of satellites). This data can be received from the satellites themselves. Thus, a cold start is possible but will take time. However knowing what time it is and where you are (approx) should allow for a faster warm start. Most complains here are about this warm start failing.

Now it would be nice to see why the warm start fails. No signal at all? Not enough data? Stupid software? (Does it forget data?)

Any ideas?