Symbol not found: _TSRMSLS_FETCH

I am trying to call CG(function_table) from within my PHP_RINIT_FUNCTION() and from what I have found I need to call TSRMSLS_FETCH() first to populate the function table in a thread safe way. When I run the extension I get: dyld: lazy symbol binding failed: Symbol not found: _TSRMSLS_FETCH Referenced from: /Library/PHP5/lib/php/extensions/no-debug-zts-20060613/vardumpoverload.so Expected in: flat namespace dyld: Symbol not found: _TSRMSLS_FETCH Referenced from: /Library/PHP5/lib/php/extensions/no-debug-zts-20060613/vardumpoverload.so Expected in: flat namespace Any pointers? Is there a more specific mailing list than php internals to get help with writing extensions for PHP? I don't want to bother people here with my newbie questions unless you don't mind. Thanks Christoph