The installer has been giving major problems now (for me personally). But here is a link to someone else with the same problem ??? http://groups.google.com/groups?q=so...net&rnum=1
First the installer dumped the CDs then after I reinstalled it started giving the same problem only i could add no sources. So i have to rely on urpmi and I would recommend anyone to resort to the "command line" until the bug is fixed.
I haven't reported to Mandrake yet, but do you think that would help?