I've done some testing the past few days;

1. Left the device next to a window for 15 minutes, A-gps disabled. No lock. Not too surprising due to sub-optimal conditions.

2. Same as above but with A-gps enabled. No lock.

3. Sat on balcony under clear blue sky and tried point 1 & 2 for 15 minutes, no lock.

4. Stood on a bridge for 15 minutes. No lock.

5. Took a long walk (around 4km), a-gps enabled. No lock.

At my wit's end now. Gonna contact Nokia