No, on the network itself is no firewall between the Windows and the Ubuntu PC. And for all tests I also switched off my personal firewall on the Windows PC (zonealarm).
With an enabled clipboard in Xming successfull remote logon really only depends on former local logon at ubuntu machine. Using the strange disable-clipboard-workaround I can successfull remote- logon with and without active zonealarm on my windows PC. -- GDM sometimes does not start correct on XDMCP remote session https://launchpad.net/bugs/62031 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
