Messenger and Windows2000 Server DHCP + DNS

Hi to all,

Previously, I had PC connected in a network and set IP address, DNS
manually. The Gateway all done manually. MSN could upload file transfer
easy, no going slow, all very quick on a cable connection.Gateway was a
router, and DHCP set by the router.

Decided to change and let Win2000 Server allocate DHCP instead of the
router. Set DHCP to know about the router and so on same for DNS and domain
resolution. Switched off DHCP in the router, but made an overlap just in
case some artefacts lurked about.

Try as I might, but the file transfer on MSN stops and starts and the flag
in MSN messenger, message is slow comes up and transfers are dead slow now.
Is the routing not right in the DHCP or DNS in Win2000 Server? Dang if I
know where it needs this entry. Any ideas?

All normal web functions, browsing, news, mail all works fine from all PC's.

TIA