DNS Names

Ok here si the issue. When doing a ping or such type lookup an ip use to report back a name correctly as an example: TPAPC01.

But now suddenly we get back wierd names like:
ACA80337.ipt.aol.com

I cant figure this one out. I have checked my internal DSN and WINS and everything looks good there. All users are pointed to the correct DNS server via DHCP. The only change that was made to the network prior to this starting was we switched form DSL to a Full T-1, but I still can’t figure out how that would cause this issue, when the internal DNS server does not rely on the ISP whatsoever!

Help me!!!!!!