Mac os lion & rails & rmagick Image Failed to manipulate with rmagick, maybe it is not an image?

Question

Ruby on Rails

Problem - "Image Failed to manipulate with rmagick, maybe it is not an image?"
I searched all the forums, I realized that if you have xcode 4 and lion 10.7, then problems begin with rmagick - the image cannot be cropped and the application hangs on the rails, who came across, how was it treated?