I've patched raterfarian again because I needed some changes for my newly purchased prs505
This version let the user select how many shades of gray (with thanks of jakeluck for the shades)
But most importantly, the batch function is now usable.
Get it here:
http://kmfstudio.com/rasterfarian_252_patch.html
Just extract and overwrite the files in your rasterfarian directory. A install version will be released later.