wapbl causing hangs

[Mark Davies <mark%mcs.vuw.ac.nz@localhost>]

On a dell poweredge 1950 running current from a few days ago I have a 
couple of filesystems that are identical except one is mounted with "-o 
log" and the other with "-o softdep".  If I try to copy approx 34GB from 
another machine to the softdep filesystem (via "tar | ssh tar" or rsync) 
it works fine, but if I try to do the same to the wapbl filesystem the 
whole machine hangs after a couple of GB.  Unfortunately the machine just 
hangs solidly without any indication of what happened.  Any suggestions on 
what I can do to try and get more info on whats going wrong?

cheers
mark