John,
I can't help much, but in case you need to try something different, consider trying rotctl (hamlib) to manually send commands to the LVB tracker. This way you can at least be sure that it's not a computer issue (although it doesn't appear that that is possible).
The only other thing I can tell you is that neither of the meters on my G5400B controller work (one is never even remotely close to the actual position, and the other doesnt move at all) - yet the value displayed on my Fox Delta ST2 are always dead on and the rotators track position perfectly. Good luck!
--Roy K3RLD
At the time the azimuth needle sometimes bounced all over the place, if I tapped the box it affected it too. Sometimes the azimuth meter swung all the way right to 450 degrees and seemed stuck.