IUSR Has Old Name Causing Problems

This is Server2003 Std R2 and it has IIS with a public facing site. It is on our network with a local IP and access, both LAN & WWW, is controlled by firewall rules. Recently, due to a long story, the name of this server was changed from C10007 to C10222. I began getting a lot of DCOM errors on an application we run and have determined it's a permissions issue related to this naming change. When I look at the security properties of a folder and if I wanted to add a user, there it is, but really strange. My Internet Guest Account is showing as (C10222\IUSR_C10007) This is the current name, but showing IUSR with the old name? I've done some research on the DCOM errors and thought I had it fixed, but not.

I think this, the naming issue, is the real source of my issues and need to know how to fix it, or to help it out. There are a few other things that happen with profile specific programs every now and then that also have indicators they are related to this issue. Below are some samples to help show what I'm talking about when I mention the name, etc.

 

Any constructive thoughts / ideas please?

C10007 is the name the server was, and C10222 is the new name after some other issues and it was renamed. I wonder if the old name showing up is causing issues with permissions on some items when it's no longer the name? Also, why wouldn't it recognize the name change or bring this up out of some hidden cache? Just to clarify...I went all the way down to the NetBios name to see it really did change to the new name...??