Mucks,
The real reason for dual boot is that my office work demands that I have windows for several reasons, otherwise it is always a good idea to have a clean installation with just one OS as it is always stable and does not disturb the other OS in anyway. You may have noted that the real pain at times is the MBR and if not properly set up it can render the system useless and both OS would fail on startup. I have had these probelms before but did also manage to get the two OS work flawlessly for sometime on my home desktop.
I would suggest that you hop over to Hardware Compatibility list
here to find out if your particular HD is listed and if it works or not. It is a handy link to have and to bookmark as you may need to use it for reference in future when you start to work on other machines or upgrade some hardware on your existing machines. This list also is great to have when you intend to buy new hardware and want to know if a particular hardware would work with Linux OS and which one.
PS I just checked the list and found out that my mobile drive will work with Linux without any problem as it has already been tested (same type albeit 160GB capacity) I do not see why mine which is 40 GB should not work.