I have one that also gave mysterious "jamming" problems that nothing conventional would fix. It turns out the source of the problem was, believe it or not, improperly machined locking lugs in the slide, which were letting the barrel start rising before it should have and jam against the underside of the slide. No amount of polishing of the affected areas of barrel or slide would fix it--in fact, it seemed to make it worse. I finally cured it by replacing the slide completely with a non-ODI unit from somewhere. (Today the gun lives as a semi-dedicated .22 conversion.)
To find out if this is your problem, clear/empty the gun, hold it upside down, and run the slide back and forth several times at various speed from ultra-slow to fast. If it EVER hangs up or hesitates, congratulations, you've got the problem. (It will never show this symptom empty right-side up, but will loaded, or empty upside-down.)