I forgot some other useful step to improve usabiity of your k|ubuntu on mac.
Mounting your OS X HD
First of all you have to find wich is the right HD parttion, for example using tools like QTParted. In my case the mac partition (HFS+) is sda2
Then you have to create a m ount point, for example /media/mac or everything else you want to use.
Now it’s time to try if you can mount the partition giving this command in your shell:
mount -t hfsplus -w /dev/sda2 /media/mac/
Now you should be able to access the OS X partition.
If you want to have the partition mounted at boot time you have to modify your fstab.
Find the uuid of your partition typing as root:
vol_id -u /dev/sda2
Then edit /et/fstab (as root) adding a line like this:
UUID=12345 /media/mac hfsplus defaults,rw,force 0 0
(Don’t type 12345 but the UUID you get from vol_id)
Now you can access your mac partition in read write mode.