I am not sure I completely understand your problem, Linechaser, so feel free to reject the following.
What I think the problem is that Streets & Trips 2010 places the pushpin icons for an imported data set on your map with an unvarying, but undesirable, offset from where the icons were placed in Streets & Trips 2008.
If that is the situation, would it be possible to do a macro adjustment of your data set for instance by adding (or subtracting) a small factor to the lat/long data in you data source file? You can use ctrl-alt-C zoomed-in to the finest level to calculate how much of an adjustment you require. Then, apply the adjustment either to the lat/long data columns or create new columns for the adjusted data.