It happens long time ago, perhaps, November last year 2008. Networked Windows computers are not accessible by its computer name (hostname). We can only ping and access them via IP address.
Is it a bug on Windows?
I have found a fix on it on the internet. It was by setting the file: C:\windows\system32\drivers\etc\host into this content:
[ip address] [hostname]
Now that solves the problem.