As a workaround, start the text mode installer in Expert mode. This can be done either by pressing F6 and selecting Expert mode in 9.04, or by pressing F6 twice in previous releases of Ubuntu, or by specifying priority=low in the kernel command line at the beginning of installation.
The F6 methods apparently are not applicable to Ubuntu DVDs
As a workaround, start the text mode installer in Expert mode. This can be done either by pressing F6 and selecting Expert mode in 9.04, or by pressing F6 twice in previous releases of Ubuntu, or by specifying priority=low in the kernel command line at the beginning of installation.
The F6 methods apparently are not applicable to Ubuntu DVDs