Blank Screen for 30 Seconds before boot starts?

On my old Sony laptop this problem never occurs, but after duel bootng OSX and Windows 7 on my MacBook I get this possible problem on every boot.

My MacBook starts as nromal, I select Windows 7 (OSX boots fine) and it just hangs on a blank screen for around 20 seconds with an underscore flashing the whole time before anything starts to happen (that bit where the Windows logo forms etc).

This makes the boot times around 1 minute or so, whereas on my old laptop they're only around 30 seconds.

This is Windows 7 Ultimate (64-bit). Everything is updated, using Bootcamp 3.0 drivers etc, working perfectly just like XP did.

I'm sure this question has been asked before, but I have tried searching, and can't seem to find anyone with this problem. Is this just apart of booting? Why doesn't this happen on my other PC?

Thanks.

Edit: Mis-typed title, meant to say 20 seconds.

You can try looking in the system log files (from the log viewer under admin tools). Ususally if a driver or piece of hardware takes longer than expected to become active a warning it put in the log.

On the other end of the spectrum is the Windows Performance Toolkit which you can DL from here:
Windows Performance Analysis Developer Center

It is much more involved but it can possibly pinpoint a specific driver that is hanging for 30 seconds. That is assuming that the black screen is during the windows boot and is not bootcamp itself waiting for something bfore actually starting the windows boot...

Other people with my problem here: Apple - Support - Discussions - Long black screen with underscore at ...