Directory Service Event Log NTDSA Error

Hello all:

Hope you're having a great day.  I'm running a Domain
Controller with Windows Server 2003 on a Dell PowerEdge
2600 with dual Xeons and 1GB of RAM. 

In my Directory Service Event log, I get the following
error once every day: 

NTDS (520) NTDSA: A request to write to the
file "C:\WINDOWS\NTDS\edb.log" at offset 26112
(0x0000000000006600) for 512 (0x00000200) bytes
succeeded, but took an abnormally long time (92 seconds)
to be serviced by the OS. This problem is likely due to
faulty hardware. Please contact your hardware vendor for
further assistance diagnosing the problem.

I can't find info on this error anywhere. Dell seems to
be unsure, and my disks aren't showing any errors when I
run Dell's diagnostics. 

Can anyone shed any light on this error?

Thanks!
Christian