I found this thread on Google while looking for a solution. Thank you guys, but none of your tips helped. However, I found something that may help future readers. If you rub the tip of your stylus back and forth in the crack between the trigger and the system, it will clean any dust or dirt in a matter of seconds. I did this, and now both my triggers work perfectly. Not only is it convenient, but it works better than anything else.

I haven't played Marvel, but Kameo is probably better. It's one of the best launch games, if not the best. You got the better end of the trade in my opinion.