Please all of you with gps problems also check lithium backup battery on gps board. Should read around 3V ideally, if not replace it. (Needs soldering tools). Mine was empty, not to say it was (how do you say this correctly in english?) deep uncharged and did what some of the lithiums do then: it flipped polarity. (read around -250 mv) Under this circumstances it might be problematic for the chip to store satellites. Before changing it I struggled to get 5 satellites today and one hour later after the repair i got to 8 satellites within first 30 secs.
The backup battery is extremely small for the power consumption of the memory. I got my PV2+ three weeks ago and battery is dead and gone! (How long has that been inside the shelve) I replaces it with a standard 2032 to give it a bit more lifetime....