"spontaneous" transposition in cubase 5

While editting in the key editor the VSTi starts playing (approximately) a half tone higher. this is so for some time now with halion one and now it happened with philharmonic, so it’s not restricred to a spacific VSTi. it occurs spontaneously, and i can’t find where the command is set, so i can’t get rid of it.
can anyone help?

Screenshots please, particularly showing the MIDI inserts section of the inspector.