I have had several situations where the bearing of a target differed substantially when viewed on the XRX unit vs. TrueMap. I have replicated the problem several times on the ground, but can't be 100% sure of the issue since there is a time lapse from seeing it on the XRX display vs. the pc due to the switching configuration steps. Have you heard of this problem before?

I am not sure if this will address your issue, but I was having some discrepancies with displayed traffic location (as depicted on my 496) in relation to where I actually saw the traffic. I now start by using the traffic screen on the XRX to verify the magnetic heading displayed is relatively close to what the aircraft DG indicates (I adjust by slightly canting the XRX to one direction or the other). Then I change over to the GARMIN/TIS mode. While not perfect, it is better.

Thanks but the problem I'm referring to is difference in bearing as depicted on the interfaced computer (similar to your 496) and the bearing on the XRX screen - not referring to the position out the window.

Have you seen a difference between your 496 and XRX screen?

I have not toggled between the 496 and the XRX screens, so I can not say directly. When I have gotten a visual on traffic and there appears to be a significent delta between displayed bearing and actual bearing, I reorient the XRX relative to the longitudinal axis of the aircraft by a compensating number of degrees. While it is not a cure-all, it seems to help a little.