Sorting empty cells

[muscaiu]

Here sorting works well:

But on descending order, the table displays blank rows 1-st and the data at the end. It is the same thing with every column, not just Date.

How can i make it ignore blank rows, and display real data before the blank rows?

The table looks like this:

    <th md-column md-order-by="datacoll">Data Colloquio</th>
     ...
    <td md-cell>{{ item.datacoll | date :'MMM dd, yyyy HH:mm'}}</td>

[muscaiu]

Will try another way to ask this, since i get no reply.