I know that on a 1500 if it cranks but won't start until you let go of the starter button it is the battery, Sorry but I'm not sure about a 1200, but I would guess if it acts the same way it probably is the battery. Batteries can last from 1 year to 5 years, a good rule of thumb is replace it every 3 to 4 years, better off to do that than be stuck some where with a dead battery.
I have a 1999, 1500A. I had much the same problem with mine. I had a stock battery but I would act much like a drained battery, but then start. I had the battery checked and found it to be bad. When I put in the new battery I couldn't believe how much faster it cranked. Even with the mod battery, I would have a shop check battery condition. If the battery is about to dump, that could be the problem.