Get a list of all registered taxonomies outside the loop

Hi everybody,
I tried to get a list of all registered taxonomies (even the custom ones) as an array outside the loop in WordPress 3.4.2 and the new WordPress 3.5 Beta. I tried it with the get_taxonomies() function in the functions.php within my theme.
All I got when I do a print_r(get_taxonomies()); is this array:
Array ( [category] => category [post_tag] => post_tag [nav_menu] => nav_menu [link_category] => link_category [post_format] => post_format ).
There are a bunch of other, custom taxonomies, filled with custom posts but they do not appear. What went wrong? Where is the mistake?

Any help would be appreciated!
Thanks in advance
Ameisenman