#1 Thumbnail selection does not work correctly

[Dominic]

Steps to reproduce:
1) Enter in item ID which has several images that can
be used as thumbnails
2) Right click on the item's row, click ShowItem
3) Right click on the item row, then click Image >
Change Thumb

Expected: Images to appear in buttons in dialog pop up
Actual: none appear

4) Click on several of the buttons
Expected: Thumbnail image to change
Actual: Nothing happens to thumbnail image