Unexpected OOP behavior

I noticed a behavior of my PHP class (4.1.1) which I found very unexpected and also undocumented. I defined a class constructor, and this constructor was automatically called *again* on my instantiated object when the script ended! This runs counter to 1. what one would expect a constructor to do 2. what the PHP docs say, which is that any clean up of a class object must be handled explicitly Can anyone verify/explain this behavior? Thanks Rich