Well I have similar problems with DVD installation (stopped at one specific tar) and then I/O ERROR
I thought DVD might be burned not properly, but I burned it again let MDchecked and it was ok, ran again the installation -> same result I/O ERROR
Then I thought DVD drive might not work properly, replaced the DVD dirve, same result.
Now I think it might be the M/B
0710 Beta 4 is running perfectly
it is only 0710 RC2 that will not install from DVD (as above). CD installation finishes ok, but MCE does not want to start on my machine.