Question : SBS 2003 DNS Errors

We are running SBS2003-R2.  From time to time (I haven't kept close track, but I'd say about once every couple weeks) the server will just become unresponsive.  Useres are unable to logon (though if they wait long enough (like 30 minutes) they are sometimes able to get logged in) and I can't logon to the server console either.  Forcing a shutdown and restart (via power cycle) brings the server back up and everything is fine after that.  Looking in the event logs it apparently has something to do with DNS -- particularly events 4004 and 4016.  I have attached a screen shot of the DNS log while this is occurring and right after the hard reboot.  I've also attached a copy of the netdiag and dcdiag outputs.  We do host our own email, but other than that it is a very clean straightforward SBS2003 install.  Any ideas what causes this DNS issue(s)?

Answer : SBS 2003 DNS Errors

I made a few adjustments to the NOD32 AV configuration per the following KB articles:

ESET KB#727
http://support.microsoft.com/kb/822158
http://support.microsoft.com/kb/823166

Since making the changes I have not had any issues with the server.

[Thanks Bamit99 for directing me past DNS.]