SBS 2003 DHCP Service Stopping - Events 1053, 1054 from DHCP, not

In the last week or so, the DHCP service on an SBS server we run has been
stopping itself, not through a crash, but through the service controller,
like its being stopped normally. However, before it stops, two errors show in
the event viewer:

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The description for Event ID ( 1053 ) in Source ( DhcpServer ) cannot be
found. The local computer may not have the necessary registry information or
message DLL files to display messages from a remote computer. You may be able
to use the /AUXSOURCE= flag to retrieve this description; see Help and
Support for details. The following information is part of the event:
192.168.1.28, , 0.

================================================== =

The description for Event ID ( 1054 ) in Source ( DhcpServer ) cannot be
found. The local computer may not have the necessary registry information or
message DLL files to display messages from a remote computer. You may be able
to use the /AUXSOURCE= flag to retrieve this description; see Help and
Support for details. The following information is part of the event: , , 0.

================================================== =

192.168.1.28 is getting a lease from the DHCP server about half an hour
before these events occur. I'm not sure what type of machine it is - this is
a remote site that allows users to bring in their own laptops. Once it stops,
it can be started again without a problem, but we'd like to know why its
stopping in the first place!

Thanks

--
Andrew Walman
Citric Technology Limited