<p>Why does Leopard mangle some symbols with $non_lazy_ptr?  More importantly what is the best method to fix undefined symbol errors because a symbol has been mangled with $non_lazy_ptr?</p>

From:
Developer Connection - Indirect Addressing
Indirect addressing is the name of the code generation technique that allows symbols defined in one file to be referenced from another file, without requiring the referencing file to have explicit knowledge of the layout of the file that defines the symbol. Therefore, the defining file can be modified independently of the referencing file. Indirect addressing minimizes the number of locations that must be modified by the dynamic linker, which facilitates code sharing and improves performance.
When a file uses data that is defined in another file, it creates symbol references. A symbol reference identifies the file from which a symbol is imported and the referenced symbol. There are two types of symbol references: nonlazy and lazy.
Nonlazy symbol references are resolved (bound to their definitions) by the dynamic linker when a module is loaded.
A nonlazy symbol reference is essentially a symbol pointer—a pointer-sized piece of data. The compiler generates nonlazy symbol references for data symbols or function addresses.
Lazy symbol references are resolved by the dynamic linker the first time they are used (not at load time). Subsequent calls to the referenced symbol jump directly to the symbol’s definition.
Lazy symbol references are made up of a symbol pointer and a symbol stub, a small amount of code that directly dereferences and jumps through the symbol pointer. The compiler generates lazy symbol references when it encounters a call to a function defined in another file.