Snow Blowers

I have a 6-year old 1130SB-XLS. The drive mechanism is slow to engage - especially when very cold. Cycling between reverse and forward a few times seems to help. Once warmed up it works fine. Not a new problem - it has been like this since new. Wondering if others have had this problem? Thinking it might be a little ice build up on a belt? Wondering if it is best to leave the machine in reverse, forward, or the neutral position when storing?