custom errors handling class

hi, I need some help, this is my problem: I use a custom errors handling class, which set one of its methods as the php errors handler. All works well when I use this class in a file with only procedural code (all errors are caught by the custom errors handling class), but if I instantiate another class in this file, and in this class I have a error, this error is not caught by the custom errors handling class that I defined, instead is caught by the implicit php error handler. My question is what can I do to make my custom error handling class catch all the errors, even if they are in another class that I have instantiated? thanks, Mihai