These are the types of issues you have with cell phone GPS. Sometimes you will get down to about 6-10ft. Other times about 90 ft is as close as you can get.
Part of it is hardware, and part is software. The idea is the more sats you can get locked in to, the better you accuracy. Download GPS Status, and you can see if you are able to lock into more then 3-4 sats at once.
Will do, I was using my sanyo katana with the trimble geocacher and it was right on all the time, so far the moment has not gone below 90ft, might just be time to get a real gps I guess .