Product Sort Arrows have gone missing

[axiomx11]

When viewing products in the administration section, there are usually arrows for moving items up and down in the list.

 

The html for that looks something like this:

 

<td>
<a href="categories.php?cPath=2_8&action=move_product&pID=1243&id=352&direction=up">
<img src="images/up.gif"/>
</a>
<a href="categories.php?cPath=2_8&action=move_product&pID=1243&id=352&direction=down">
<img src="images/down.gif"/>
</a>
</td>

 

Instead, my store shows no arrows, just the ID number, like this:

 

<td>1238</td>

 

Advice on how to get my arrows back?