Try 'computer management' in win7 control panel and make -unallocated- the space after win7. Then right click 'new volume' and size. Don't assign letter or path and not formatted. Right click, 'make active' and close. It will mess up your booting into win 7 but using 'boot132' iso disk you'll be able to boot up and install kalyway 10.5.2. The new volume partition you created you will choose after disk utilities ,erase, pick 'journeled extended' and install to this partition.

I might add that win 7 adds 100mb Fat partition 'win reserve' that messes up gparted and Guid in osx messes up reinstalling win7 or vista. If those happen I had to pretend to reinstall 'xp' and chose drive that you've been working on and actually delete the system on it and then choose to reformat in xp. Accept f8 and install xp only to delete later.........but at least your drive will be set to either reinstall mac osx or dual boot vista. I'll try and add link about this http://www.taranfx.com/blog/install-mac-os-x-leopard-osx86-on-pc-dual-boot-windows-7-vista-in-9-easy-steps............didn't think I'd be able to find it so quick. Good luck