Firstly - Thank you!!!
Have literally looked all over the place and took ages before I stumbled across your post.
I've got a Kindle 3 and CS5 - I've followed your instructions but I realise they should probably be a little different for CS5.
Anyway, converted two comics today and it worked no problem, when I set the third to be done I specified the input folder and the output destination but it created a single image and it had the name of the previous comic I converted...instead of the file name of the original image :S
Instead of converting every image from the original - it converted them one at a time and saved them all with the same name, saving over each file as it converted the rest, leaving me with a single image file of the last page in my output folder after the batch was finished. I'm totally confused because its just worked twice no problem and third time its gone a bit funny.
Any help would be great - once again many thanks for posting this to begin with!