I've been avoiding boot loader problems in my multi OS systems by using separate hard drives for each system e.g. a windows hard drive and a second drive with Ubuntu installed. Currently I have been avoiding multiboot problems by disconnecting the Ubuntu disk when installing windows and then diconnecting the Windows drive before installing Ubuntu. Then I connect both drives and boot the computer. The bios offers a selection of boot device if I press F8 during start up.
I wish that the Ubuntu and Windows installation disks would see this two-separate-drives installation and offer the option to not install a bootloader so I could do my installations without needing to remove and replace hard drives.
BTW: I also tried partitioning the drives with a swap on the windows drive for use by Ubuntu, and a fat32 partition on the Ubuntu drive for windows to use as vitrual memory. However Ubuntu and windows dont seem to use much swap/virtual memory on 512Mb-2Gb machines so making the extra partitions is not helpful for me.