Well I've downloaded the image a second time, yesterday was on a 10.5 iMac, today a 10.6 MacBook. I get the same as you both times. So I don't think it is RAW support on your laptop.
What is your workflow, have you got these images OK on the iMac they are fine, transfer to the laptop and corrupted? Do they then re-open if you transfer back to the iMac or are they then perm corrupted. I'm suspecting it'd be broken or I'd be getting a working image here. Imagine if you sent me the same file from the iMac originally it would work here also.
Have you got filevault enabled on the laptop? I've seen a snippet of info on one of the Apple discussion boards
http://discussions.apple.com/thread.jspa?threadID=1210713
last comment
"I have been advised that FileVault could be the culprit. I have Filevault activated on my MacBook Pro and after upgrading to Leopard, my RAW CR2 Canon images created post upgrade are all unreadable. I believe the Filevault encryption may be to blame. I am investigating but it may give others something to go on."