Dumb question but when I play sitting I don't rest my arm on the guitar because I was told to a while back, and now I've gotten good at it. But when I stand I have to rest it on there to keep it in position which is sorta uncomfortable. Is it just that my strap is cheap or does anyone else have this problem?
I also kindof have this problem with my Ibanez. Unless Im in some sort of extreme metal stance (very cool), I find it very awquard to play, especially leads. I always find myself with one leg on a chair or something, to supportt the guitar. I'm going to buy a leather strap, see if that helps at all, but for now its gonna have to be Mohammed Suimez stance.
Try raising your strap for now, see if that helps.
Raise your strap

It's a problem alot of people have, when we practice... more often than not... we're siiting down. You get used to playing in this position and when you stand up it's difficult to play guitar properly. Try raising your strap to a comfortable height, then lower your guitar strap a little every now and then so you get used to a lower height till it's as low as you want it to be.