I've had my new 2003 tassajara for 2 days now and on the 2nd day of riding the chain was skipping horribly. When ever I was pedalling with increased torque, the chain would jump gears and sometimes not catch at all, one time resulting in the pedal carving up my leg. Any insight into this? The bike shop guy took a quick look at it before he closed shop and said that the lines need to be tightened on a new bike after an initial break-in? Is this true? I hope its nothing serious or costly since I just bought the bike and if it can't take a rough ride then the bike is near useless for me.

-c