said Dan Youngquist:
| Might try moving or deleting the .trinity folder first. If it's a | Trinity configuration problem, that might take care of it.
thanks. actually, you sparked me to go check my ~dot-directories to make sure there was nothing that night be conflicting. i detected a couple of possibilities in the form of old .kde/ i'd saved for reversion if upgrades didn't go well. renamed 'em, rebooted, and so far the symptoms are gone. (though they were never present right at first after a reboot.) fingers are crossed. i've kept my desktop pretty much the same for about a decade, so i know how to make it back into what i like, but i've never enjoyed it and would just as soon not do it again!
anyway, you tapped the lightbulb and made it go on. thanks!