SAV server can't see clients

I have a Server running here (first time using it) and I thought it was running fine until I noticed that the help desk was not using the managed install of SAV. I instructed them how to do it the right way, but I still have a few out there that ...... This is what I did. I told them to install the GRC.DAT file under the ...7.5 folder. It took and the clients are now looking at the server. But my server can't see them. Is there a setting I'm missing in the server? I found the work around, uninstall and reinstall the app. That's all nice, etc except that this is Baghdad and it's difficult (to say the least) to get to the guys that are in and out of combat to stay in one place. Any experience on this issue?