Intrepid Ibex on Mac

I've been using II Beta for a while, and before that I had tried the Alpha for a few weeks. The biggest problem I had was that Yakuake 2.9.3 didn't work as it should in that I couldn't assign a shortcut key (or combo) open or close it. I was forced to place its icon in the AWN dock and manipulate it from there.
So, even though my II Beta was fully updated, I still hoped that doing a clean install of the released II would get Yakauke back for me.
I installed it yesterday (without formatting /home) and the install went fine (other than a huge booting problem which I'll describe shortly).
Note that, rather than installing it directly from the install CD, I used the command

ubiquity --no-migration-assistant

due to problems I had with this before.
Unfortunately, Yakuake still wouldn't work properly. Plus the Fx keys (eg F12) don't seem to be recognised by the Yakuake shortcut function any more. I tried both Ctrl-Y and Alt-Y as shortcuts to open/close Yakauke. Both seemed to work OK to close it but not to open.
So, it seems I'm going to have to email that Yakuake developer guy to see if he can suggest a fix.

And now that boot problem. When I tried to reboot after successfully installing Intrepid Ibex, the rEFIt boot screen was totally white. Eventually, a grey question mark showed up but no boot options were shown.
I had a similar problem before and resolved it by reinstalling Grub (from Ubuntu / to MBR) and by using Gparted to remove the boot flag from all Linux partitions (although only one ever had a boot flag -- that on /dev/sda3).
So, I used the II Live CD to reinstall Grub but this made no difference to the featureless rEFIt boot screen.
Next I tried Gparted 3.0 Live CD. However, I didn't get too far with this. Although it got as far as showing the partition table, once I touched this the CPU use rose to 100% and everything froze. I did this many times, and used nearly all of the boot options on the LiveCD, but none worked.
What did work, however, was the Local Boot option which brought up the full Grub menu and allowed me to boot into II. From there I was able to install Gparted from Synaptic and take out the boot flag on /dev/sda3 after which the rEFIt boot menu reappeared. Now, I had to sync the GPT and MBR tables in rEFIT and then re-install Grub to get everything back to normal.