When you stated that you are differentially correcting the data, are you post-processing? If so, what coordinate system are you post-processing your data in or exporting to?
When you navigate back to points are you using SBAS for real-time accuracy or are you tied into a VRS/RTN reference network?
10' off is quite a bit, and seems to be more than a coordinate system issue. Is 10' just an example or is this an average for most features?
Brett