Option to export i3d not working

I got the newest Blender 2.7 and newest python installed ok. And imported my model everything worked great!
I installed “io_scene_i3d” to C:\Program Files\Blender Foundation\Blender\2.62\scripts\addons but It still dosent
show i3d as a option to import or export. I checked the all the stuff in the custom import/export area but no luck.
Others seem not to have any problems so any clues???