I installed the latest rEFIt with a clean install of 10.5.2, which I had formatted into three partitions with diskutil (JHFS+, ZFS, JHFS+) on my Santa Rosa Macbook Pro 15" 2.4Ghz C2D
When I used the partition tool in rEFIt to make my MBR table, which until then only showed the EFI partition, it worked but back in Mac OS X whenever I use 'diskutil list' it will say:
Ge64:~ Ge64$ diskutil list
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *149.1 Gi disk0
DiskManagement setuid-tool failure
I've done this twice and completely re-wiped my drive to start over after this happened but now it happened again, exactly the same situation. I have used rEFIt on this macbook succesfully before to triple boot and had no problems at all.
Disk Utility will also 'lose it's connection to the disk manager' whenever I try to erase a partition on the disk.