DNS Netmask Ordering / Round Robin

[efector]

I am working on an issue with deploying some MS ISA servers. Without full babble, each ISA(which is in a different AD "Site"), is configured with its unique host name, that is registered in DNS.

In order to make it transparent to the end users, I am configuring a single "A" record(this is kinda the config MS says to use).

Example:

isa01.foo.com - 10.0.0.2
isa02.foo.com - 10.0.0.3
isa03.foo.com - 10.0.0.4
(all 3 in different AD sites)

They then recommend you create the following:

isa.foo.com - 10.0.0.2
isa.foo.com - 10.0.0.3
isa.foo.com - 10.0.0.4

You then configure user's machines with the A record of "isa.foo.com".

Pretty simple eh? What I am running into, is that in some of my sites, they are not returning the correct local subnet address for isa.foo.com

I've been reading that Netmask Ordering is important to be on, which IT IS. Also, ROUND ROBIN is turned on. Is somehow Round Robin conflicting with the Netmask Ordering? Is it one or the other?

Also, as a twist, all DC/DNS servers are 2008 R2, in all sites, except the one that is working(that one is 2003 R2). Is this a problem with 2003 R2?

Any help you can provide would be great.