The story is now on two pages, and I may no longer remember every detail, so I will try to summarize what we know. Correct me if I missed something.
The issue seems to be intermittent. Your GPS setup (laptop + USB GPS receiver + navigation software) can get a good lock on several satellites while your truck is parked, but while the truck is in motion, the setup will likely only get a lock on 2 or 3 satellites, or none at all.
You get the same results:
- with different USB GPS receivers
- before and after you reformatted your hard drive
- with different GPS software
- with or with out USB hub
and nothing has recently changed in your setup. You are using the same hardware, software, and the same truck.
The next thing I would do, is to try your setup in your car, instead of the truck.