unable to set parking brake

[tiburon]

Hi,

I recently finished a little throttle console with some switches to use with the PMDG 737, I assigned the switches to the offsets for engine start and parking brake through the OC USB-keys card and FSUIPC, everything worked flawlessly.

The other day, however, I tried to start a flight and was unable to set the parking brakes ! Not with the assigned switch, not by mouse-clicking on the parking brake, not by using the key combination ctrl ., nothing moved the parking brake.

What I noticed however was on another networked computer where active sky and some other applications run through WideFS my parking brake switch, only connected to the FS computer, was changing the tabs in Firefox !!

I tried disconnecting everything and although the strange behaviour in Firefox stopped, I still could not move the parking brake. Tried restarting FS, reloading different airplanes, nothing.

I hope somebody can give me some explanation as to what could cause this strange behaviour.

regards

Martin