domain.local not availible to the Permissions >Location button

[solidfusion]

I'm trying to let a user on the domain have share access to one of my folders on my local machine. I know that in order to do this I have to select the user from the domain provided by my Windows 2003 server. I am able to do this on 2 machines, but the other 4 for some reason aren't allowing me to do that. I set up all the machines alike and I can't figure out what's the problem. Even on those machines that do work, once in a while when I go into the permissions dialog box and click on location only the local computer name shows.

Any suggestions? I think it must be a setting with my Windows 2003 server, perhaps dealing with Active Directory. Also, the computers that seem to work I can access their logs from the server, and get the message that they can't find the computer on those that it doesn't work.