Linux MCE does the same for me. I have a custom network setup (wireless bridge which converts into an ethernet switch) running via typical DHCP perfectly. Ubuntu understands the DHCP for this weird setup and has NO issues out of the box. Ever. As soon as I (attempt to) install Linux MCE, the installer screws up my network config and sets it to something NON-standard (tries to run its own DHCP server?!) and I can never get it to install.
Installing Vista Media Center doesn't break things and actually works fine for me.
I WANT to use Linux. Too bad this is not worth the trouble.