Sharepoint Image from html content not displayed in Reporting Services

Hello,

I try to display a sharepoint column "Publishing HTML" that contains text and images in Reporting services (the option HTML - Interpret HTML tags as styles is activated).
The text is visible correctly but no image is displayed. The source code contains the tag "img" with the correct image address (tested in the navigator) but it does not seem to be interpreted correctly by Reporting Services.
Any idea what is wrong?

For information, Execution account for Reporting services has been changed with a full right account but it does not solved the issue.

Florian