I haven't had that problem either. I work the bolt pretty hard, and once I got over my fear of a slamfire, I resisted the temptation to ride it home while loading.
In fact, the only failure to feed I've seen was the result of riding the bolt home instead of just releasing it and letting it go on it's own.
Have you tried loading fewer than 10 rounds to see if that changes the way it feeds?
Jerry Miculek demonstrates loading from the bottom in his SKS review, I thought it was interesting: