Hi Kevin,
I doubt the problem is your keps if you have an up to date set from any of the sources suggested.
You might want to check the following:
Your PC clock may not have the correct time There may be something in an initialisation routine that has set a default time zone, or an offset from UTC This can be tricky with some PC's and software. You might have to set your PC clock to UTC. Entering your lat/long, East or West of the Grenwich (0) meridian. There is no convention on this some programs want a plus sign ahead of your longitude some a minus.
Those are the things that have caught me out in the past.
BTW - dont expect agreement to the second between different tracking software. Its only a prediction and not all programs use the exact same algorithms to do the calcs.
Good Luck
73 John G7HIA