I have one of the new front load energy efficient washers. If the clothes are left in the washer for a few hours after they finish washing they begin to have an odor. Anyone else have a similar problem?

Where does the water drain tube go to? Does it go into a sink or directly into the plumbing? If it's the later you need to make sure that it's connected in front of a trap or sewer gases will leak back into the washer. I'm pretty sure this is code for most areas.

I goes diretly into the plumbing in a drain installed for the washer. The clothes smell and there is no smell coming from the washer when it is empty.

Unless there's no trap installed after the point where the drain connects in I wouldn't know. I suppose it could be mildew but a few hours doesn't seem like enough time for that to happen unless it's really warm in there.