Sometimes when adding a UNIX namespace you can get the following message:
"CAFT Message: Transfer time limit exceeded UNIX NIS Directory"
The reason for this is a combination between the network and the fact that default protocol for CAM/CAFT is UDP.
A possible fix is to change the protocol on both the server and your clients to TCP.
On your server:
camconfig *paths "etrust.nis protocol=tcp"
On your UNIX client:
cd 'cat /etc/catngcampath'/bin
./camconfig *paths "<YOURSERVERNAME> protocol=tcp"