Just a heads up. I'm running WP 3.4.2 with Term Menu Order 0.4 and Events Manager 5.2.3. When I go to Events > Event Categories and Quick Edit one of the categories, there are two 'Order' fields that pop up. If a value has been entered, then neither field is populated with the value.
I don't know if it's a problem with other custom taxonomies or just particular to EM.