What's an xid Mismatch?

[Martin McCormick]

This just started today and our syslog is full of these
messages. It is always the same client and he appears to
register his DHCP lease, but why am I getting this complaint?
stw is the peer name.

	Thank you.

Dec 15 08:22:40 dh1 dhcpd: DHCPACK on 139.78.118.164 to 00:c0:4f:38:81:b9
(JERRYBR) via bce0 
Dec 15 08:22:40 dh1 dhcpd: Added new forward map
from JERRYBR.bael.okstate.edu to 139.78.118.164 
Dec 15 08:22:40 dh1
dhcpd: added reverse map from 164.118.78.139.in-addr.arpa. to
JERRYBR.bael.okstate.edu 
Dec 15 08:22:40 dh1 dhcpd: DHCPREQUEST for
139.78.118.164 from 00:c0:4f:38:81:b9 (JERRYBR) via bce0 
Dec 15 08:22:40 dh1 dhcpd: DHCPACK on 139.78.118.164 to
 00:c0:4f:38:81:b9
(JERRYBR) via bce0 
Dec 15 08:22:40 dh1 dhcpd: bind update on
139.78.118.164 got ack from stw: xid mismatch.  
Dec 15 08:22:40 dh1
last message repeated 19 times

	I think the client is broken because he has been
hammering us every few seconds to register and then getting
right back in the registration process a couple of seconds
later.