You are right!
Remember that funny message I received when I initially tried dragging RUMlogNG into the applications folder? That must've caused some funny system cache thing due to permissions. I may not have had the proper permissions set for the older RUMlogNG file.
I copied and pasted the new RUMlogNG into the Applications folder instead of dragging it. Of course, it asked if I wanted a second file there. I said yes, then deleted the older RUMlogNG file, and renamed the new one from RUMlogNG 2 to RUMlogNG. That fixed it.
It survived an Onyx cleaning and a restart.
Sorry for the alarm!