jppaz wrote:
How did you do it?
Assuming no conflicts with whatever Wordpress htaccess you have going, just do a full backup, install a fresh copy of G3 wherever you want it, copy over the var folder, update the db login info (if needed), and (optionally) enable redirects from the old directory to the new one. Once it's all working as expected, rename the old folder. If it's still working as expected after the rename, you should be able to delete the old folder.
NOTE: If you're just moving from folder to folder on the same server, you can likely keep the same db settings.
http://codex.galleryproject.org/Gallery3:FAQ#How_can_I_move_my_gallery_installation_from_one_server_to_another.3F