Problems installing CAELinux 2009 from LiveDVD

Hello,

I am trying to install caelinux 2009 from the live dvd
on an imac 27 i7 with a ati radeon hd 4850 graphic card.

The first problem appears at step 3 of the installation.
The keyboard configuration does not work. After I select
french then macintoch and try to continue I get the following
message:
partman crashed
partman failed with exit code 10

and I get nowhere trying any of the suggested options:
quit - continue anyway - try again

Also I tried other keyboard configurations with the same
result.

I would really appreciate any help.

Thank in advance
Michel