Download problem... LyX dmg "not recognized"

[Bettina]

Hey - I want to dl LyX for Mac. I tried it on the Download page
(http://www.lyx.org/Download#toc4), but ftp login and password are required.
When I downloaded the LyX-1.6.7-Mac-Universal.dmg file from CNET, the disk image
could not be mounted... Anyone who could help me out?
Thanks!