Two months ago it was around ten degrees and my friends sportsman 500's 4 wheel drive didn't work when he turned the switch on. We thought it was the cold weather because it worked the next day. Last month our 250 did the same thing! It worked later that day. Both times we were pulling a shanty. Both cases involved pulling an ice shanty. The 4x4 light comes on but only the back wheels spin. Does anyone else have this problem?