It's funny, power steering fluid seepage never dawned on me as a probable culprit.  It's funny especially because, as one of those "while I'm here" items, I did check the level.  It was good.  But I didn't look closely around the fill opening to see if there had been any leakage.  And, of course, everything's closed up again at this point  
 
I can probably take another gander at it before the end of the week...