The Refresh button on the VMWare Server action doesn't actually involve VMWare at all, it just uses the NetServerEnum API [1] to get a list of servers. You can also manually enter the computer name in the Computer field.
The attached sample worked in my tests w/ the VMWare Server RC (v1.0.0 build-24927) on the server, and the VmCom lib (from the same installer) and VBP 6.1 on the client computer (of course, specifying valid server, user, password, and .vmx filename values). Be aware that firewalls or other networking software can block communications if not configured to allow it. Also, the Machine field must be the full drive+path+filename to a .vmx file (relative to the server) or a regex that matches the full filenames of the machine(s) to be manipulated.
http://www.visualbuild.com/Manual/vmwareserver.htm
[1]
http://msdn.microsoft.com/library/de...serverenum.asp