I would suggest following checks:
a. Are both virtual machine reacheable to/from eachother ? Try using ping.
b. Make sure you have made correct changes in /etc/yp.conf (hostname or ipaddress of ypserver machine), /etc/sysconfig/network (entered domainname entry)files.
c. portmap service is running on the client.
d. configured client using authconfing utility to set client to look for yp server for authentication.
e. If still not successfull then do these steps and post the output:
service ypserver restart (on stattion1)
service portmap restart (on station2)
service ypbind restart (on station2)
ping me on yahoo messenger to have an immediate look into ur issue.