I posted the following comments in bugzilla:

-cold fix times are much shorter if the antenna is pointed to the south (in the north hemisphere) than towards the north. This suggests that the GPS chip does not use the correct doppler shift.

-hot fix times are short if a cold fix was done using the wayfinder map application. If I use, say, maemo mapper only, hot fixes are not shorter than the first fix (cold fix), suggesting that almanach or last position data is not saved correctly when using another application than the wayfinder map application.