I am also having the uncontollable gunfire sound problem.  I have tried to submit a ticket but after logging into my account 2-7-11 at 14:05 EST, when I click on the Submit new ticket link it doesn't take me anywhere.  I will keep trying, but to inform others following this thread, when I fire using the #1 button on my Saitek Aviator joystick ( I have used 2 different ones, same result) I get the firing visuals which are synchronized to pulling or releasing the button but the gun sound starts and never stops.  I tried different guns, same result.  Changing from guns to missiles or rockets has no effect.
Yes, I read the manuals.
I'll keep trying to submit a ticket but so far, no joy.