View Flow does not show the image

Hi

When I click the "View Flow" image, no image is displayed.
I've ensured the site is setup for "Scripts Only".
I've set the Local Intranet for "Full trust" (.net 1.1 config).
I've added the site (an alias to the real server) to my intranet zone in my browser.
I have permissions to view the process.
I have read the other posts and KB articles which generally suggest the above.
The server console says "Marshalling: ViewProcessInstance".

The three knowledgebase articles do not work for me.
Any suggestions?

Where is the temporary image created? I suspect the K2 service user (or the impersonated user) does not have rights to create the temporary flow image.