I have a series of scheduled tasks that all run at various times of the day. Since the migration from Coldfusion version 7 to 10, these tasks have stopped running.
For me the requests were timing out. I increased the timeout in the administrator and that solved it. Doing a cfhttp in a test file and dumping the results helped me troubleshoot it.
Is the scheduled task folder has any check for the session or anything? I mean is the scheduled task folder is accessible without login? Please try with removing all the redirect rules for the application. That might work.