In my case (official 10.04 Ubuntu desktop disk), I get these "end_request: I/O error, dev sr0, sector 506112...606172 (the last ones visible on screen)" messages after CD has been ejected. Pressing Enter on this state does not reboot the system, I have to press the reset key. Also Ctrl-Alt-Del does not work (maybe it even should not work).
I tested this three times (i.e. installed the system three times). The same error message was given on all times after CD was automatically ejected and Enter did not reboot the system in any of these.
In my case (official 10.04 Ubuntu desktop disk), I get these "end_request: I/O error, dev sr0, sector 506112...606172 (the last ones visible on screen)" messages after CD has been ejected. Pressing Enter on this state does not reboot the system, I have to press the reset key. Also Ctrl-Alt-Del does not work (maybe it even should not work).
I tested this three times (i.e. installed the system three times). The same error message was given on all times after CD was automatically ejected and Enter did not reboot the system in any of these.