database broken

I'm getting a "database broken;" at least once per day now.  My dcc_db 
is over 2 GB and has been for a while.
The automatic repair runs, but it really bogs down the box in the middle 
of the day.
Is this typical of anybody else?

I run dbclean every night and I've tried setting
DBCLEAN_ARGS="-E 7 DAYS"
in the dcc_conf, but it doesn't have any effect.
The server barely has enough disk space to keep its head above water, so 
I need to do something...
(Sorry if the answer is in the manual... i've got a lot of anvils in the 
air at the moment, so I haven't had time to RTFM)