When I try the "Creating GIF images" example from the php manuel I always get a broken image. The PHPINFO.PHP3 file says that i have GD support enabled (1.6.2 or higher) and TTF library.
try looking at the page-source of that 'broken image', see what it says.
It says: "Warning: ImageCreateFromGif: No GIF support in this PHP build in C:\Apache\htdocs/images/button.php3 on line 4". But I have the .dll file and its registered in the php.ini.
GIF support was dropped from GD because the owners of the GIF routines started chargins money for it's use.
Instead of GIF, use PNG or JPG.