Shared object "libX11.so.6" not found

["Larson, Timothy E." <TELarson%west.com@localhost>]

I began seeing this message appear onscreen while xscreensaver is running.  I 
suspect it may have something to do with the fact that this was a NB 4 box 
upgraded to NB5 so it's a bit confused between R6 and R7, but why haven't I 
seen this earlier?  Anyway, what do I do to clear this up?


Thanks,
Tim