NW5.1 / SP7 / NFAP SP4

I installed NFAP on two servers in a tree and now the tree is no longer
being displayed in Network Neighborhood, but the Server does display. I
can still login to the server successfully with no errors, and once I
login to the server it will then show up in Network Neighborhood, but
still wont display in Client32.

I didn't have this problem when I installed NFAP on a test server in a
seperate tree.

Any ideas? Thanks in Advance,