FC4 test 3 failure during installation

[M K]

Hi!

I downloaded the FC4T3 DVD image and burned it to a DVD-RW disk. I
started the installation and selected "minimal installation". The
installation got stuck when a message "An error occured unmounting the
CD. Please make sure you'r e not accessing /mnt/source from the shell
on tty2 and then click OK to retry" popped up. No matter what I do I
can't continue. Please note that I've not done anything on the virtual
console.

Any ideas?

MK