Nslookup shows multiple hosts for a single ip address

I am running a 2003 AD integrated domain. I have recently found if I run:

nslookup 198.100.10.150 (on a particular ip)

(i get:)

Server: Server.Name.domain
Address: xxx.xxx.xxx

Name: host.name.domain
Address: 198.100.10.150

But if I run the command again I get a different host for the same IP. 9 different hosts cycle thru before it returns the original host name again. Would this be a cache problem?