File type does not meet security guidelines

Hey

I have two different users on my blog (2.7.wp), one is an “administrator”, the other one is in a “editor” role.

With the administrator role I’m able to upload a *.flv file to the media library through the normal post editor, but if I try to upload the flv file with the “editor” user, I get this error message:

File type does not meet security guidelines. Try another.

How can I allow the “editor” to upload a flv file, without upgrading him to an administrator.
In the wp_usermeta table, there is a field called “wp_user_level”, where the admin has 10, and the editor has 7. I tried it also with 8 and 9 for the “editor” role, didn’t work either.

There are some other posts about it, put in the new version, you can’t go to MIME-TYPE settings, and I don’t want to change some core files, because through an upgrade those get probably overwritten, don’t they?

Thanks