Been trying to Boot Camp with Vista Business x64 onto a new second disc without any luck - says windows is unable to find a volume that meets its criteria - and now on restart the mac is stuck in a cycle of booting from the DVD. I have tried holding 'd', option key, option+cmd+o+f, and mouse button but it still keeps booting from the DVD. I was using an Enterprise 32bit DVD earlier and I could eject that by holding the mouse button down on startup 
Please help!

Please help!