> btw, I forgot to mention that high CVS update (i.e. disk) load was also in the mix :-/

An additional data point that I should have mentioned (I got a private 
e-mail asking about softdep).

I had /usr mounted with softdep. The directory /usr/src was one of the 
directories often being updated using CVS.  For the moment I've stopped 
mounting things softdep.

enjoy,
Andrew