Keyboard key issue

[Bobb4]

Every now and again while flying online (co-op) I lose several mapped keyboard controls. Either landing gear/flaps or...
It is always rather random what stops working. As these are co-op missions there is no hitting refly
I first noticed the issue when I installed windows 7 and I was wondering if anyone has any advice.
As I say it is very random, can fly six missions in a row without and issue and then I take off and my flaps do not raise
I use windows 7 32bit