I have a Studio XPS 1645 with Windows 7 Ultimate 64 bit

I resized the NTFS partition to make room for a Ubuntu 10.04 Linux install.
It installed fine and runs beautifully. Booting into Windows however corrupts
the MBR or the bootloader (GRUB2).

After loading Windows 7, I cannot successfully boot the system.
Each and every time I must re-installed the bootloader (GRUB2) and then
reboot the system to be able to load either Ubuntu or Windows. Loading
Ubuntu doesn't cause problems btw. It's definitely something to do with
Windows 7 or the pre-installed software, like the Datasafe Local Backup,
etc...

Anyone with any suggestions, ideas, comments, etc...?

I've performed the hardware test, HDD is fine etc...

Cheers