[Opendnssec-user] drudger message

[Jon Knight]

We're running version 1.3.3 of opendnssec at the moment and I've just 
notice that we've been getting these messages appear in our 
/var/log/messages:

Nov 23 14:38:09 hostnamer ods-signerd: [fifo] max cap reached, but drudgers seem to be on hold, notify drudgers again

I did a Google search to try to find out what this message means but came 
up empty handed... can anyone throw any light on it?  Is it something we 
need to worry about?  FWIW these are often repeated thousands of times in 
short periods.