I've said it before but I'll say it again. I think the best way to boot between multiple linux distributions/partitions etc is to download and install smart boot manager (find with Google). It is a simple boot manager which lives entirely in your MBR (i.e. independent of any partition), is completely menu driven, allows you to change and save all boot parameters, label partition names with your distribution/version, etc. Whenever you install a distribution just install lilo/grub into the start of partition instead of the MBR. Smart boot manager will find it and be able to load it.

Experienced software engineers that when you have an apparent obstacle/imbalance then you can often use indirection to solve the problem. That's the pattern being applied here.