W2K3 SP1 name resolution issue?

Greetings,

I have a couple of Windows 2003 servers that recently had SP 1 applied.
Occasionally, these boxes will loose communication with remote systems
(there are applications running on the w2k3 server that telnet to specific
ports on remote systems to transfer data). At the time when the
communication drops, I can not manually telnet or ping the remote host -- it
responds rather quickly saying that it could not open connection to the
host: Connect failed.

Now, I can do a nslookup on the hostname and it resolves correctly. If I
use the 'repair' option for the NIC, it seems to clear this up and
communication is restored. This happens somewhat infrequently, but enough
to be a pain.

I seems like it started right after SP 1 was installed.

Anyone have any ideas??

Thanks a bunch!!

--Eric