And if that's a no-go then perhaps try a gparted live media.
1) backup your stuff, just in case 2) get gparted http://gparted.org/livecd.php 3) boot off it and prepare the partitions, e.g. a simple setup would be: *a swap partition size of your RAM if you intend to hibernate *at least a 10 gig ext4 (for root) *rest (for your home), xfs 4) then try the install again and choose manual partitioning
