I mostly make pan settings with the mousewheel, for step by step changes.
With miditracks: mousewheel down = pan goes left; mousewheel up = pan goes right.
With audio and instrument tracks: reversed !
It happens in the mixer and in Inspector.
More people having trouble with this ?
It happens here in Cubase 5 and Cubase 6 on two different machines.
Windows XP sp3 | Cubase 5.5.2 | Cubase 6.0.0