My went away for the weekend and, when I came back, I found my copy of Limewire 2.63 PRO running as an Ultrapeer even though the settings had a checkmark for Disable Ultrapeer (and it's worked properly until now).

Known bug?

No, - that's really strange. Did you set FORCE_SUPERNODE_MODE=true in the props file? LimeWire seems to behave weirdly if you disable and force ultrapeer mode at the same time, although most of the time it will stay in leaf mode.

I didn't do anything in the config file by hand... except that I am running the PROPS.JS file from my previous install, LW 2.55 PRO. I made a backup copy of it before installing 2.63 PRO (beta). Sure enough, my PROPS were erased for some reason. I replaced the new/reset file with my backup copy and everything's been running fine ever since (over a week, I think).