Sweaty hands?? well, guess what? today is your lucky day my friend!!!!!! I had the same problem until yesterday, forget about all those loco tricks you used to try....... hahaha now I sound like one of those boring advertisements that show on TV at 3am.... no, what you need is to get yourself a smudge guard... i just got myself one and is a real blessing... just go to www.smudgeguard.com and you won't regret it, I did't.
P.S. hope I don't get in trouble for making advertisments of other sites, if i'm violating any rule just let me know.