samba - Nov 2003 - 2.2.7a doesn't appear in network neighborhood

Hi,

i recently updatet Samba 2.2.1 to 2.2.7a-SuSE using my old config files. 
But now the server doesn't appear in the network neighborhood (Win2k) 
anymore. If I explicitely search for the server (using the windows 
function) i can find it - but I have to do this on every machine...

Any hints?

thanks,
Kai