I'm trying to set up dual-boot on my MacBook Pro, and have run into some questions. I used Disk Utility to allocate some free space for Ubuntu, and now I'm in the Ubuntu installer's partitioner.

There are already 3 partitions on my disk. One is EFI, one is for Mac OS X, and one is I think for recovery. I want to make a partition for Ubuntu and a swap partition. First I created both as primary partitions, then remembered I can only have 4 primary partitions, so I made the swap partition logical. But why did it let me set them both as primary in the first place? Does this mean one of the existing Mac partitions is logical? Or would it have messed up if I'd continued like that? Is there any disadvantage to making the swap partition logical?

My next question is about the bootloader. Since Macs use EFI not a BIOS, I read that I shouldn't install the bootloader on my MBR, which I assume is the /dev/sda choice. Instead, I changed it to /dev/sda4 which is my Ubuntu partition. I got a dialog that "The partition table format in use on your disks normally requires you to create a separate partition for boot loader code...". Should I continue or do I need to change something? I have installed rEFIt.