Error: File not found when address the site with full computer name

Today, I have an interesting thing while I am working on SharePoint. My co-worker gets an error when he try to access the SharePoint site by IP address. Of course, he can fix this issue, that means it's so easy, at least with him. However, it still shows error if I address to his site with full computer name. You know, when your computer join to the domain, then your computer's fullname is your computer name dot domain name.

In this example, my computer name is htserver2k8x64 (or vm_moss2007x64), when I join to the domain with named "tuan-tomy-blogspot.vn" then my computer's fullname is "vm_moss2007x64.tuan-tomy-blogspot.vn". The problem is if I browse my site from http://vm_moss2007x64 or http://htserver2k8x64 (for windows server 2008, 64 bits), everything works fine. After that I changed to http://vm_moss2007x64.tuan-tomy-blogspot.vn, with the team site without my web part that everything is fine again. But if in the team site included my web part already, I got an error like this:

Then, I removed my web part out web part zone, then added my web part again, I got another error:

Yeah! for now I just did the following SharePoint instruction. In this case, I must add new alternating access mapping in the Central Admin.
Go to Options -> Alternating Access Mapping -> Add internal URL for Port 80 ( I am working on Port 80)

Then you will see 2 internal url can access to the same web application:

For now, you can access the site by http://vm_moss2007x64 or http://vm_moss2007x64.tuan-tomy-blogspot.vn without any error.

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For another solutions, you can modify the Host header of your site in IIS:

This solutions is also resolved this issue.