There is evidently either a difference in Fascinate units in the GPS or in the way some come set up for GPS out of the box. I'm on my second Fascinate. The first one was dead on accurate right out of the box. If I went to the middle of the road, I could tell what side of the yellow line I was on. The second one simply refused to work anywhere close to acceptably. Multiple minute location fixes that may have been off by a mile or more. I have had had had used GPS Status for a year or so. When I got the second fascinate I did the GPS Status>menu>settings>GPS & Sensors>Manage A-GPS. It didn't work. It didn't work that is until about the sixth or seventh time I had done that. I had removed root and uninstalled all root related apps and was going to go back to Verizon and plead for a different unit. Well, I checked GPS Status what I thought was one last time, and lo and behold it seemed to be working. The location was off by a hundred feet or so, sometimes less, but at least I was close enough that My Tracks and Navigation were spot on. I went into GPS Status settings again and checked GPS required and I checked strong filtering as well. The strong filter said it would slow the lock time down and it did, from three seconds to four seconds and I was again able to get close enough with the GPS location to tell which side of the road I was on. By the way, it did not work any differently initially with root removed, I just removed traces of root to avoid the whole root thing if I went back to the Verizon store, which began to look inevitable.
Now I have no idea what is going on here, except that maybe it just took several A-GPS reloads to finally either get a good file, or maybe just download it properly. So I'd be a bit persistent with the GPS Status A-GPS management.
The one thing common to both Fascinates where I am is that they both had a very annoying tendency to drop data connections, something that almost never happened with my Droid 1. So maybe I was having dropped data connections at just the wrong moment and the A-GPS file did not download properly.
Now I HOPE this keeps working.