I checked my old server and I find the following.
xxx.xxx.xxx.xxx_xx.rev is present under /etc/bind and this file contains the records for xxx/xxx.xxx.xxx.xxx.in-addr.arpa
I am not able to see the same thing on the new ISPConfig server..
I also note that the file names are different.
old server = example.com.hosts
new server = pri.example.com
I am sure the name is not really anything.
The big question is why things are not showing up..?? It has got to be something really simple that I am missing..