Short story: partition resizing using **Disk Utility** fails because **MediaKit reports no such partition** when I try to shrink it. I also tried the same while booting from the DVD, same result.

Details:

* reFIT is installed and partition tables are in sync.

Current configuration:

* refit
* hfs+ - with OS X 10.6 on it
* linux swap
* linux ext4 - with Ubuntu on it

I can boot both, OS X and Ubuntu, via [rEFIt](http://refit.sourceforge.net/) boot menu but **I want to shrink the OSX partition in order to add another NTFS partion where I want to install Windows 7 x64**.

What should I do?
![enter image description here](https://i.stack.imgur.com/WYGxZ.png)