Members Gallery itself actually has a different set of sorting options from a normal gallery and that wasn't accounted for in the Admin or on the showmembers.php page.
In adm-cats.php at line 225, the one line:
Code:
Content visible to verified customers only.
should be changed to:
Code:
Content visible to verified customers only.
and in showmembers.php at line 122 the line under the comment should be changed to:
Code:
Content visible to verified customers only.