Have others successfully booted from a "dual partition card"?
I got d10-100b-1.1.0-2401-full_BETA running on a 4GB card without problems.
THEN I tried a 8GB card. THe only method to get this particular hardware (an Eye-Fi Pro X2 8GB) working was to use Linux, create a 4GB partition in both fdisk and with mkfs.vdos and put CHDK on this.
As soon as I added a second FAT16 partition (just for testing) the camera seems not to boot CHDK from the write-proteced SD.
I just bought the camera in the hope that I could start some construction-time-lapse project with it.