My QuickGPS on my Diamond has to be redownloaded every week, its set up to automaticly do it.
This is Shadow-Techs fix. It works miracles but I think you would need data for it to work-->
http://forum.ppcgeeks.com/showthread.php?t=36377
heres something else to try, I think its similar to QuickGPS. Its what I used on my Vogue before doing the fix and it always seemed to help.
If you choose menu on googleMaps then click use GPS it will start looking for sats and show how many its locked.(see screenshot)