Check this, I do remember the system I built long ago had a similar problem and after spending quite a few days, I found the cause was a faulty IDE cable, I used the one that came with the mobo but it was soooo chinese... err sorry I mean cheap.
Change it and re test, hopefully you will fix it.
Right, SteamWake or the message:
Please insert the next floppy disk and press any key to continue... When you are installing from a cd.
