[fel64]

In functions.php, find the get_profile_info_keys() function …

Much neater to pluginise it like the avatar plugin has done than to hack around in the core files, but that’s the solution now anyway.

I’m not sure how the hook ardentfrost used works specifically but the sensible thing for it to do would be to pass the infokeys array as a parameter (just like the allowed tags hook), in which case you could easily add onto whatever was already in the array. If someone’s interested it might be worth testing, again as the neatest/least problematic way of doing this.