I didn't change any code at all on my side. Updated to the latest version of FPE 3.1 now my physics objects are not moving at all. No errors either.
the "Step" method is being called as it should...
Comparing the source for FPE 3.0 and 3.1 I see there's been a lot of changes to compilation symbol checks. FPE 3.0 only had checks for "SILVERLIGHT" but 3.1 has checks for "SILVERLIGHT;WINDOWS_PHONE"
I'm wondering if some timer code is been lost with these conditions so they're not triggered??