Adam,

 

We are currently on 5.3.   We were planning to upgrade to 6.0 later in the year, unless there is a reason (like this issue?) to upgrade now.   Your example displays the images OK on Firefox here, the only difference I see is the specification of the path of the image.

 

If you have a test website (let's call it 'TEST') which contains an .aspx page in which the editor is defined, can you recreate our problem by putting, for instance, a .jpg file (TESTFILE.JPG) into the root folder of the website, putting the following HTML into your editor and then viewing that page through Firefox?

<div><img src="\TEST\TESTFILE.JPG" border="1" height="200" width="200"></div>

Thanks