Strange problem with WINS

Hi Everyone,
I have a strange problem with a grading software program. It prompts you
for an IP address of the grading server when opened. Here is the strange
part. If the 98 client has the DHCP server dole out the IP & WINS server
addresses, I type the address 10.10.10.10:123 it takes 20 to 30 seconds to
get the prompt for a login, and it works fine until I close it and it takes
a long time to close. If I give the client a static IP and put the WINS
servers directly into the TCP/IPsettings of the client, and type the same
address 10.10.10.10:123 the username and password prompt pop up almost
instantaneously. Now what is strange is that if I type in the name of the
server like this:servername:123 on those slow clients it opens up
instantaneously. Does anybody have any ideas? One other note is when I
use the nbtstat -A 10.10.10.10 for that server's IP address I get "Host
not found". When I that has anything to do with it or not. I have
successfully released and refreshed that server with the WINS server. I
don't have the problem on machines running XP. Thanks in advance for any
suggestions.

pete