pardes,

It's not uncommon with triples for the chain to drop. Since the bike is new, the cables will require adjustment after 100 miles, but it's probably not a chain problem per se.

I encourage you to go and spend about $20 at the lbs and have them install a "third eye". It's wonderful!

It goes on your seat tube next to the chain ring:

http://www.icyclesusa.com/catalog/th...in-watcher.htm