Windows 7 and hard drive shutdown problem

OK guys my problem is that when I shut down my computer (properly using the shutdown option in windows 7), my disk when it spins down makes on odd scratching noise only for a second though. I have made sure that nothing is interfiering with it inside-i have 1 cable underneath it which doesn't even touch it and also a few cables on top which do touch it but that doesn't have any moving parts so should be ok.

So essentially how can i solve the problem of my disk making this noise on shutdown- is it like an emergency park or something?
I am scanning my disk now with western digitals own utility my drive is a Western Digital WD5000AAKS 500GB SATAII 7200RPM 16MB Cache - OEM Caviar Blue. The quick test was fine I am just running the extended test at the moment.

Fast reply would be appreciated because I want to turn my computer off without my hdd making that noise again- unless it's normal of course...

EDIT: Does this drive just have a loud spindown?

Thanks