I had GSS2.5 on domain1 (2008 server). We just changed domains to domain2. I uninstalled GSS 2.5 and all 3com boot tools. and reinstalled them and started fresh with new pxe image and bootptab templates. The only thing that has changed is we added DHCP to this 2008 server and as a result we cannot run "proxydhcp" under 3com PXE Server.
When we boot the computer (client to get the image) we cannot connect to the 3com PXE serveri get error: no boot filename received.