Hi, unfortunately it is not the parking brake, it must be another program which I have recently installed, because I just ran a test with everything loaded and CTRL + F12 did not do anything. When I closed everything and reloaded just FSX, CTRL + F12 worked fine.
The only new programs I have added are FSCaptain and IVAP (I was on vatsim's FSINN)......
ahh haaaa, I think I have found it!! The IVAP configuration has CTRL + F12 assigned to squawk ident, I will unasssign that and report back