No, that's not right. Does it show only on one particular mission? Could you have accidentally deleted a camo file in the BoB registry? You can have all sorts of fun doing things like that.
I've had that whining for a while but I thought it might be the PSU fan vibrating against the casing - but that too quietens down after about five minutes. I'll have to check everything re the connections.
'Find your enemy and shoot him down - everything else is unimportant.'