CS 727-100 corrupts P3DV2 to the point that a P3DV2 repair does not work. A full uninstall/reinstall is needed. Apparently same goes for the 707.

The folks from the Estonian Migration Tool team seem to have a HotFix for this issue.  However, I am not quite sure whether you need to buy the tool to take advantage of the fix and whether it needs to be run every time your previous session used a CS aircraft.

I am planning to run FSX and P3DV2 in parrallel. Would be keen to hear other people's experience regarding CS aircraft in P3DV2.

Thanks