That error indicates a badly burned DVD (or possibly a corrupt ISO file). Verify the ISO and reburn to good quality media; use a slow burn speed if necessary.
how do i verify the iso? i opened the checksum file and it seems okay, anything else i need to do to verify it? i tried different dvd's it didn't work. maybe the beta and final release will fix this.
if anything i can wait for the beta or final release, it'll probably be fixed, and i can wait, it's not a big deal i guess... not if it's this much hassle.