Odd performance problem

Hello,

While debugging a script that ran too slowly I came across something that I 
can't explain.

It is inactive code that when removed doubles the run time of the script.

Specifically, the issue is a switch statement, where one of the cases is 
never reached. If I remove the case from the code, the run time of the 
script goes from 6 seconds to 12 seconds.

To see this problem in action, you can download the problematic script here:
http://sebrechts.net/files/2008/phpperfissue.zip

Anyone have any ideas on how this is even possible? I'd like to improve the 
run time of the script, but if every part of code that I take out makes it 
run longer ...

Thanks