I would suggest applying the latest updates on ColdFusion.
CF is fully patched and up to date - was there a particular patch you have in mind?
I think I know what causing the error. For some reason, that "1" was included in the JSON output and caused the error. In CF Admin, there is a setting to debug AJAX. Turn it on and trace it by looking at the output from AJAX.
Enable AJAX Debug Log Window
Allows display of the AJAX debug log window when the cfdebug flag is passed in the URL. If you disable this option, the AJAX debug log window does not display, even if the cfdebug flag is specified.
I am having the same issue. If I remove my header file or merely blank it out, all works fine. Problem is that I really need to display the header file. Is there some way to tell JSON to ignore my header file?