Long pause before Vista boots

Windows Vista waits for 50 seconds with a black screen and blinking text cursor "_" before the splash screen begins (the green loading bar).

Any ideas of how to fix this? Although not huge problem, it's delaying the boot by quite a bit, seemingly for no reason.

I've got a feeling it might be due to MBPs having EFI instead of BIOS, but what do you think?

Thanks.