Seems nothing wrong with your script, seems that no info was send to the script. I'd say there is soming wrong in either your html, or something in apache was altered.
I still do think you should be far more expressive if you want a solution, show us some html (form methods, submit methods (via JavaScript?) info about your apache setup etc.
as stated before, something won't just stop working like this.
I'd even try to check a system with a program like checkrootkit to see if the system is still 'clean'
"We all agree on the necessity of compromise. We just can't agree on when it's necessary to compromise." - Larry Wall.