Image Editor doesn't work on web farm

Hi Telerik Team,

We use Telerik ASP.net controls in our project. We found the Image Editor doesn’t work well on web farm environment. In our production server, we uses Image Editor three ways.
    1. RadEditor -> Image Manager -> Image Editor
    2. Using customizing existing Image Manager dialogs Image Manager -> Image Editor
    3. Using Image Editor directly

The first and third ways works perfect but the second way doesn’t work on web farm environment. You can check attachments for the source code and fiddler screen shoot.

Any clues?

Thanks in advance,

Lan