image functions are 'undefined'

[perunaion]

For starters, Windows XP using IIS with PHP 4.3.4 installed. Very straight forward. I'm running a thumbnail script and I'm having a problem where all of my image functions are considered undefined function calls. imagecreatefromstring() imagesx() imagesy() etc. I have uncommented the "extension=php_gd2.dll" line in my php.ini. Yet it seems to have no affect whatsoever. From what I've read this is what I need to do. When I run phpinfo(), it shows the gd as installed and running properly. Any ideas as to whats going on?
Thanks.

[weekender]

make sure the dll is in your extensions_dir, and copy all the dlls into windows/system (i think)