This is more likely to be user error than a bug.
The menu shows Mac OS and Windows, but does not show Ubuntu.
How do I get into Ubuntu or make it appear on the boot menu?
See Partition Inspector report below:-
*** Report for internal hard disk ***
Current GPT partition table:
# Start LBA End LBA Type
1 40 409639 EFI System (FAT)
2 409640 66417503 Mac OS X HFS+
3 66679648 168181799 Basic Data
4 168181800 234441607 Basic Data
Current MBR partition table:
# A Start LBA End LBA Type
1 1 409639 ee EFI Protective
2 409640 66417503 af Mac OS X HFS+
3 66679648 168181799 83 Linux
4 * 168181800 234441607 0c FAT32 (LBA)
MBR contents:
Boot Code: Unknown, but bootable
Partition at LBA 40:
Boot Code: None (Non-system disk message)
File System: FAT32
Listed in GPT as partition 1, type EFI System (FAT)
Partition at LBA 409640:
Boot Code: None
File System: HFS Extended (HFS+)
Listed in GPT as partition 2, type Mac OS X HFS+
Listed in MBR as partition 2, type af Mac OS X HFS+
Partition at LBA 66679648:
Boot Code: None
File System: ext3
Listed in GPT as partition 3, type Basic Data
Listed in MBR as partition 3, type 83 Linux
Partition at LBA 168181800:
Boot Code: Windows NTLDR
File System: FAT32
Listed in GPT as partition 4, type Basic Data
Listed in MBR as partition 4, type 0c FAT32 (LBA), active
There is no Linux boot loader on your system, so the Linux install is not bootable (with or without rEFIt). I'd assume this happens when you install Linux first, and it puts GRUB into the MBR by default, which is then wiped out when you install Windows because Windows puts a generic chainloader into the MBR.
Generally the fix is to boot into Linux from CD, and tell it to reinstall GRUB, preferably in the partition boot sector -- in your case /dev/sda3 instead of /dev/sda, or in GRUB notation, "(hd0,2)" instead of "(hd0)".