I just came across a known bug in ColdFusion 8.0.1. Apparently, sometimes the ColdFusion image functions don't play nicely with JPG image files and throw the following error:
An exception occurred while trying to write the image. Ensure that the destination directory exists and that Coldfusion has permission to write to the given path or file. cause : coldfusion.image.ImageWriter$ImageWritingException: An exception occurred while trying to write the image.
Some quick googling found that there was a Hot Fix available for ColdFusion 8.0.1 image functions. I figured I would post it here in case anyone was running into the same problem.
I installed the above ColdFusion 8.0.1 Image hot fix, restarted my ColdFusion service, and the image that was breaking my application started working again.