First of all. There are 2 different "naming mechanisms" in Windows:
1. IP Name Resolution. It works with all legacy IP applications (Internet Explorer) and utilities (like ping, tracert, or telnet). System resolves names either through "hosts" file (stored in c:\windows\system32\drivers\etc), or through DNS (internal or external).
2. NetBIOS Names. This names are used for "Network Neighborhood Browsing", file and printers sharing, etc. (i.e. Microsoft Networking). NetBIOS Names can be resolved by 3 ways: WINS server (have to configure in TCP/IP properties), LMHOSTS file (stored in the same folder with HOSTS file), or by LAN broadcasts.
So, you can be able to resolve name in "ping" utility but be unable to share files with a server and viceversa.
You may ignore "ping" part of troubleshooting and look at NetBIOS part. First of all, check if you have anything configured in c:\windows\system32\drivers\etc\lmhosts file. If you have this file created, you may just add correct entries into this file and reboot your workstation. But this way is not scalable. Since you have Windows 2000 server, it would be easier to install and enable WINS server on that machine. It's very easy and strightforward. Then either modify your workstations' TCP/IP properties (WINS Tab), or modify your DHCP Scope.
And last thing, why you may have screw-up with 192.168.0.43 address - check all workstations names in your network. May be you have a workstaition with name "server1" and it may answer to broadcast request faster than real server.
If you have more questions, send me e-mail.
Michael Shavrov
CCNP, CCDP, MCSE W2K, Security+, ...