Oh, yes, that's probably one of the bugs in the current cvs code. It won't connect when the size of the gnutella.net file is 0 bytes. Try using a new gnutella.net file (copy it into the same folder as the rest of the files) you can get it here:

ftp://whitedragon.dyndns.org/gnutella.net

(If it really didn't work on MacOSX it wouldn't even start. For almost everything else, there is a workaround. )