with a bit more searching than I really like to do, I found that others have experienced this also, and it's caused by having the "reduce flicker" set to auto/on rather than turning it on when you need it.
Just a word to the wise for anyone who has experienced/wondered what's up.
Dunno if it's with the new firmware or what, but that's supposed to fix the problem.
I've found that applying a small amount of Mike Crash's Noise Reduction filter can do wonders with this sort of thing, without introducing a lot of ghosting or reducing the resolution by much. I had some shots with LED lighting that refreshed at an odd rate that were smoothed out quite nicely using this filter.
And this is a thread where the keywords might pop up for some poor sap in the future that needs to know how to fix what he's got, as well as prevent it from re-occurring.
Arguing about trivial stuff on the internet is exactly like this great video...