When I was installing, I got this error from Ubuntu (dialog)
The installer encountered an error copying files to the hard disk:
[Errno 30] Read-only file system: '/target/tmp'
This is often due to a faulty hard disk. It may help to check whether the hard disk is old and in need of replacement, or to move the system to a cooler environment.
Sounds like exactly what it says on the tin: you probably have a dodgy hard drive. Or you might have done something interesting during the partitioning stage - did you manage disk partitioning manually, or did you tell the installer to use the whole drive, or...?