Kato N Scale Mikado w/DCC

[rlandry6]

I have a couple of spots on my layout where my Kato Mike literally loses power and stalls. I can tell because the headlamp dims. If it's rolling at a decent speed, it will roll through the "dead' spots with just a little hesitation, but it's noticable non-the-less. it doesn't seem to matter if the loco is dead-heading, or pulling a load. I've cleaned the suspect sections of track to death with a Bright Boy. None of my other locos9diesels) have this problem on the "bad" spots of track.
The Kato Mike picks up power through the tender's wheels. I'm wondering if some weight in the tender might correct this. If so, how much weight? It seems that if the track were warped, uneven, out of guage, etc, then all of the locos would be affected.. Any ideas? I'm open to sugesstions...