I'm having a very similar problem.
I've downloaded Windows 7 RC x64 from microsoft site, and I have a .iso file. Then I burned it into a dvd, opened still in Vista x86 (since it's x86, I have to do a clean install) and checked all the files in it. All seems ok.
I reseted my HP pavillion dv5 and changed boot priority to dvd first, but when it boots with the Windows 7 RC, only the blinking trace in the upper left corner of the screen appears, then it proceeds to the Vista load screen.
I tried to boot other dvd's, and the x86 Vista and an Ubuntu booted perfectly.
Does anyone have a clue on what may be happening?
Thanks in advance