You may have to load some modules before you hit <enter>.
I'm not sure about this, but if you press F1 instead of enter you will get another screen that should give you some more options, including the ability to load certain obscure pieces of hardware. You may have to load a raid driver or something like that?I don't use raid so I don't know off the top of my head.
The first thing I'd do though is change your thread title. It's too generic. You seem to have a problem installing Mandriva using a DVD drive on a raid controller, so why no include that? Unless I've got the wrong end of the stick - wouldn't be the first time