VM Names overwriting each other

I have Server 2008 running with 4 Server 2003 VMs.  The main machine always shows up in WSUS as current.  The VMs though get overwritten on the WSUS server.  server1-vm1 shows up in WSUS, but then if I do a wuauclt.exe /detectnow on server1-vm2, server1-vm1 goes away and server-vm2 shows up on the WSUS server.  Why is this happening?  Is it because the second, third and fourth VMs were created from a template of the first VM?

Thanks!
Dave