I've never used the old-style constructors, but perhaps the semantics of "parent::" changed and you need to instead use "$this->" as in $this->Tag("option", $name); That's a total guess. I don't have 5.2 handy to try it out, but both work in 5.3 using a simple example. Can you post the constructor of one of the Tag subclasses that work? Maybe we can find a common denominator. David