No, you didn't :)
Thing is that when you logged using GFC account and using WP account at the same time plugin will log out you from WP account and log you in using WP account which corresponds to your GFC account.
There are a few ways to solve this problem:
1) Log out from GFC account each time you go to admin page. Not very convenient, ha? ;)
2) Grant WP user which corresponds to your GFC account with admin rights.
BUT before that:
a) change password for this user!
b) tell plugin to use password you set instead of default one. To do that you need to edit gfc_plugin.php file. Find gfc_pwd_from_id function and replace it with something like this:
function gfc_pwd_from_id($gfc_id) {
if ( $gfc_id == 'PUT_HERE_YOUR_GFC_ID') {
return 'PUT_HERE_PASSWORD_YOU_JUST_SET';
} else {
return 'p_' . $gfc_id . '_s';
}
}
Hmmm... That's all I guess :) Good luck!