Sorting by object type attribute doesn't work properly in alphabetical order

Issue Summary

When viewing Assets objects in the list view, sorting by object type attribute does not work properly in alphabetical order.

Steps to Reproduce

1. Create an object type containing a Object attribute type. 
2. Create some objects and populate the attribute with different values for each objects.
3. Change to object list view and try to sort by the object type attribute.

Expected Results

The list should sort the object attribute by alphabetical order.

Actual Results

Some objects are returning in alphabetical order, but there are several that are returned out of order.

Workaround

There is no workaround at the moment.