I Have some trouble getting dual booting working on my macbook pro late 2011 model with ssd.

I installed rEFIT. And made a live usb fromubuntu-11.10-dvd-amd64.iso . However I didn't use the +mac version that found later on.

I made a 2gb swap partition and 35gb / partition after the mac partitions on the ssd.

Basicly the installation went well, but after restarting I came to grub menu and not as I expected the rEFIT menu. From the grub menu I cant seem to boot into OSX The screen just goes black.

I can however boot into Ubuntu.

Any suggestions how to fix this?