HFS+ Journaled

My expieriences resizing a HFS+ Journaled partition with OSX to make room for NTFS partition for Windows Vista dual boot scenario:
I tried to resize a SATA drive using the Live CD but Gparted could not resize the drive and reported that the partition table could not be read. All options were greyed out.
I read somewhere that Journaling might be the problem.
I disabled Journaling using  diskutil disableJournal /dev/disk0s1
Gparted was able to beautifully shrink my HFS+ partition and create a new NTFS partition from the unallocated space.
Hope this helps someone with similar problems.