This behavior can be observed in your production demo page of the RadEditor. http://demos.telerik.com/aspnet-ajax/editor/examples/overview/defaultcs.aspx Reproduction Steps: 1. Scroll to the table under "Attractions" 2. Right click and select "Table Properties" 3. Select the "Image Manager" next to the "Back Image" textbox 4. Select anyone of your images, I have reproduced with any of the images select "beach.jpg" 5. Click OK. The image is now visible in the table. 6. Right click on nay cell in the table and select "Cell Properties" 7. You can make a change, or not to the cell properties, and click "OK" button at the bottom. 8. You will now see that the background image is no longer present on the table. If you try step 8 again, and click on the "Table Properties" tab of the Table Wizard, you will see that there is no value in the "Back Image", so the "OK" is submitting the blank value.