Internal Server Error with renamed CGI script

I have a CGI script that runs, and does exactly what I want it to do. The problem is that if I rename the file to a different filename, it fails to run–regatdless of what I rename it to. If I rename it back to the original name, it works just fine. Permissions are set properly, it’s a UNIX end-of-line file, and there is no reference to the filename within the file itself. I checked the error log, and it gives the following error:

malformed header from script. Bad header=HTTP/1.1 200 OK: /home/xxxxxx/


If it calls itself, have you made sure to clear your cache between runs after renaming it? is it a perl script?