A couple patches ago I started having problems with my number four engine in all my bombers, it won't throttle up and my bombers go veering off the runway. I've tried selecting the number four engine itself and it just doesn't want to throttle up. It's a really weird problem and only seems to affect the number four engine. I went through all my keymapping and stick mapping and nothing's been changed, so I'm not sure how to go about fixing this one, very strange problem, any suggestions?