Snow Blowers

I purchased a single stage snow thrower in December, the ST131. I tried it in December when we had 2 inches of snow. After about 15 minutes, the drive stopped working. I shut it down, and later fixed after realizing the belt had pulled off. Then the next snow it ran fine for about 30 minutes before the engine ran rough, backfired, and quit. I figured maybe I had bad gas, so today I was ready to try again with snow coming. As I was about to start it with fresh gas, I heard the muffler fall off. So maybe I have had 45 minutes of run time with a brand new machine. I'll try to see if a dealer can service it tomorrow. Does this sound normal for Husqvarna?