Radar Contact 4 and altimeter errors

[airforce2]

I'm having a similar but more dramatic issue with offline ATC (Radar Contact)--this seems to be a problem more related to temperatures--the ambient temp set by ASXP and reported by X-Plane at FL280 is -32 +/- 3 deg C, but the temp on the PFD is wandering through a series of fairly sudden changes, with SAT ranging from -9C to -19C.  When indicating SAT at -19C (ISA +21) the indicated altitude reported by X-Plane is more than 1800 feet higher than the Challenger's altimeters.  So the RC4 controller is giving it to me with both barrels for being off my altitude.

Regards

Bob