I have a very strange problem - my speed knob acts like a wheel of fortune!  :) - Every time I use the scroll wheel on the mouse to set the speed knob on the MCP,  the value is spinning madly down and out of control. For instance if I have to go from 310 KIAS to 250 then the value is decreasing like crazy towards 0 KIAS. - The only way I'm able to stop this spinning down, is to left click directly on the numbers and hope for it stop in the area of 250 - but most often it stops way below this value and causing a lot of mess into the flight!  :(

Does anyone have any idea why..?!

All the other knobs are acting as they're suppose to (except for the Autobrake which for some reason doesn't work in VC mode)