Creating a Compact Flash image

Hi. I use a CF card to mount linus File System for an embedded system. I used the following production procedure for new CF-s:

1. Create an image: - fdisk - mount the CF and untar the parts comprising the FS there - sync+unmount - create an image using dd:

1. Once I have an image - I just used dd for every new one: dd of=/dev/sdc if=cfImage.bin bs=512 count=800

The problem: This worked fine for SandDisk 512 CF-s. It doesn't work for a bunch of new Kingston 1GB CF-s I got. The first part works fine, but I can't use an image created from one CF for another CF. If I use it for the same CF (ufter deleting it with dd from /dev/zero) - it works fine. But for some reason the image I get works only for the same CF from which it originated.

The questions: - Any idea why this can happen - Any idea for a better production procedure (its ext2fs over Linux partition in case it matters).

Thanks, Michael