I know, this is random, and weird, but I just got my first comment (for http://djay32-paperdimension.blogspot.com/2007/04/invading-castle-bleck-spoilers-included.html that entry). I have a reply.
I didn't make the videos, but I can still help. First off, I had the same problem once. I'm pretty sure you gotta go into the previous room and light all the candles as Bowser. Hang on, lemme look for a walkthrough... here! http://www.youtube.com/watch?v=jlBx7Cwokq4
Try that. And, next time, I'll reply in a comment, unless it's something REALLY important, or something.