Can't see other players in the same zone

[Kayen]

So I have a peculiar issue on my server. I can zone multiple characters to a zone, but they can't see each other. They interact with the same mobs (selling to vendors shows up for all) but not each other. Camping and coming back fixes this.

The thing that's perplexing is I don't see any errors at all. Anywhere. It just randomly does this with both static and dynamic zones.

I am using the RoF2 client. Is this perhaps an issue with that? Is there something I might be missing?

Thanks.

I can confirm this is occurring on Storm Haven and I have not even updated our source since like March/April of this year.

At least in one zone I can confirm (Valdeholm) it is happening to both myself and another player (though not all players seem to have the issue).

It is not MQ related
It is not client related (Same problem on UF->ROF)
It is not script related (disabled all scripts in zone).
You can not /target the clients who you can not see with GM commands.

Though I just assumed that this was fixed in later source update and not still occuring