Comment 6 for bug 554582

The GParted code relies on device names being in the form "/dev/mapper/..." and not "/dev/dm-#" in order to work properly with dmraid devices.

As such I think that that the following patch might be required (we include it on the GParted Live 0.5.2-9 image):
http://git.debian.org/?p=parted/parted.git;a=commit;h=c1eb485b9fd8919e18f192d678bc52b0488e6ee0