Matt, Jim, and Jeffrey,
We wanted to get back to you and let you know what we found.
1. Taking the track apart and reassembling it did not help.
2. We also noticed that sometimes the train will travel a few inches before stopping and sometimes a foot.
We looked carefully at the axels with a magnifying glass and did not see any threads. We did find a small chunck of rubbery type material on one of the wheels, but when we removed it, it did not have any effect.
3. Power plugs are all plugged in properly.
4. We didn't notice a gear slipping, but we are not experts at what the train should sound like.
5. We took all of the cars off of the locomotive and it still has the same problem (even without the tender).
Jeffrey: We are rather hesitant to open the gearbox...not sure that we could put it back together again the right way! 
We have sent in a request to Bachmann and are waiting to hear back from them. 
Thank you all so much for your help. We really love this train. It is a lot of fun for our whole family.
Happy New Year!
Cathy

Thank you Jim. My husband agrees with your conclusion on the power set up, since the light is on. We will check out all of your suggestions and let you know what we find. 
(Thank you again!)
Cathy

Thank you Matt... we will do that and let you know what happens.
Cathy

We purchased a Bachmann Overland Limited set for Christmas. The train worked fine for several days (forward and reverse) but yesterday it started to stop after going about a foot in the reverse direction. The train light is still on, but something seems to be binding the engine in reverse. Does anyone have any ideas as to what the problem could be? We are very careful about how the train is handled.

The train can be brought back to the forward direction without adjusting it's position on the track, by changing the forward and backward directions on the controller several times. Once it is put in the reverse direction, it stops again after going about one foot.

Thank you for any advice you can give.