problem playing standing

I usually go with leather straps to keep the neck from sliding, it usually works. Even with my xiphos, but I ended up replacing the buttons in the end, because it hurt my shoulder over time. But it looks like you've found a solution :)
 
it's not for all cheap guitars...my ludicrously cheap guitar (ibanez rg 2ex1 or w/e) has no problems with neck diving or string buzz or anything. If you get a well-made cheap guitar (i.e. an ibanez, tbh) you won't have these problems.

by the way, did you order the guitar online and not try it out before hand?
Because that's what's known around here as a bad call.
 
You're guitar and strap length affects you're posture when standing alot. I have a Jackson JS30RR, with this kind of guitar you should have the bottom of the guitar level with your pelvic bone and adjust your stance, placing your left foot infront of your right foot and bending the knee. wresting the guitar on your thigh is a good position for this sort of guitar, you see alot of guys play like that.... Dave Mustaine, Alexi Laiho, Randy Rhoads, who all played V shaped guitars, RR and AL especially, since the bottom wings of both their guitars are a shorter length.
 
Cheers for the input guys. I did quite a bit of research before buying my Jackson RX10D (flying v), and I didn't encounter this problem in any of the user reviews I read. I have worked out a fix to this problem by passing the strap through my belt, which prevents the neck from diving down.

Pic of guitar:
467-large.jpg

Yeah..... that ain't a King V, it's a Rhoads.