I was cutting up a sheet of 3/4" plywood as usual. I rely heavily on vertical featherboards on the fence to hold the ply in place / give me a 3rd hand. Made the first couple of cuts with no problem whatsoever.

Moved the fence a bit, made the next cut and it wouldn't go but half way through. Hmmm. Bogged down, got very hard to push, seemed to be binding. Blade got hot. Thought it might be pinching, but it was good quality plywood - not likely to pinch back around the blade. Tried raising the blade, then a cut with it even lower. Same problem. What the heck? Noticed burning/build up on the blade. Couldn't imagine it was caused by a dirty blade that had been perfectly clean a couple of days ago, but I decided to clean it again anyhow. Same problem. Could the fence be misaligned somehow? Get out the dial indicator - geez, its only off by .002" front to back, but I get it to within .001 just for grins. No way is that causing the problem. What the HECK is my problem?

This was my problem. I only adjusted ONE of the featherboards before I began, and the first few cuts I made were with the fence (Saw Train) locked in place as normal, but for the second series of cuts I had locked the fence itself down using the secondary lock which prohibits any and ALL movement of that fence. The fact that the featherboard was set too low wasn't a problem in the first set because the fence lifted up just a bit when confronted with the pressure, but it wouldn't budge on the second set of cuts, so it got really hard to push - in fact it stopped progress cold.

So I got a newly cleaned blade and a better aligned fence all for the sake of not checking the featherboard.

Let that be a lesson to me.