Maggot,
Don't know exactly what kind of malfunctions you are having, but the guys I know that use comp guns in IPSC use pretty high pressure loads to insure proper cycling. You might want to try a different brand of factory ammo, maybe using a heavier bullet. Still, I wonder if something internal is broken or improperly assembled. I have never seen a stock Glock fail to cycle properly with factory ammo. You might try an uncompenated barrel in it, if you happen to have a friend who owns a 17. If you are not comfortable with doing it yourself, take it to a Glock armoror for a checkup. Something is bad wrong!
Stay Safe,
Savage