yeah the files are crw format from chdk 1.5.0 ver 4665 running on sx120is.
adobe dng converter 8.1.0.43 won't recognize them either.
Only a few programs can recognize a CHDK RAW file - and only for some cameras.
It's much better to store the RAW images in DNG format on your camera.
Go into the CHDK RAW menu and scroll down half way to where it says DNG format. Enable that and select 'DNG' file extension.
More information about that can be found here :
DNG Format