[V8i] UNDO (CTRL+Z) is undoing a lot more than one thing!

Today I seem to have accidentally turned on the "Super-Undo" function.

Whenever I hit CTRL+Z to undo a mistake, it is undoing more than just that one action. It's not undoing EVERYTHING, but it's going back to some (apparently) random point in the design file. CTRL+R (Redo) redoes all those steps. There is no walking back or forth - it's all being undone/redone in one big sweep. This is even "working" across activated reference files - work done there is part of the undo/redo collection.

I have not set a mark and I am not Undo-ing to Mark. And it's not going back to the same spot every time. But it's definitely wiping away more than a couple of minutes work.
(Note: while I am using Power InRoads, I am not doing any design whatsoever, nor am I using the InRoads tools at all. Just plain drafting)

Has anyone ever seen this before?
Thank you.
MaryB
Power InRoads v08.11.07.615