So on start up, you don't see the option to boot either "Dell Utility Partition" or "Windows XP Media Center Edition" at all? How about moving those entries just above the line in your menu.lst that says:
Code:
### BEGIN AUTOMAGIC KERNELS LIST
Reboot, and let me know if you see either entry in your Grub menu. Also, I wouldn't recommend booting the "Dell Utility Partition", because that is your recovery partition; if you boot that and go through all the steps, it will likely erase Ubuntu and restore just Windows to your computer.