cfimage would not end its task

Hi

I'm building a little application. Mainly it's about resizing images. Actually I create from an "input" image two version, a middle sized one and a thumbnail. At the very end I would like to save all three versions in the file system. My "input" images are TIFFs in a size of about 10MB. The process would not end means that rescaling and saving does not work. Can someone tell me whether there is restrictions in size of images CF can treat?

Thank you very much