Thanks, Boys.
I'm running Bel-Ray Gearsaver, 80W. it did it w/ Golden Spectro, too. it does it only in the most extreme circumstances; right now I am laying out new trail thru tight, brushy woods & I've noticed it a couple of times when hung up in vines & such as that. I talked to the bike's previous rider, & he said it did it since new, when hung up & really slipping it. I think that, based on that + GMP & Loosenut's advice, I'll just keep an eye on it for right now.
thanks for the help!