Actually, my Uncle got a Yugoslavian SKS recently and while we were firing it at the range, it jammed up every time and even fell apart at one point.
I'm not doubting you; maybe it was just the one he had.
On the other hand they are typically totally reliable, solidly built and more accurate than the AK's. I have owned maybe half a dozen and never had a malfunction.
What do you mean when you say fell apart? Did the barreled action come out of the stock? Yugo's are very sturdy and very reliable. You have piqued my curiosity.