Document Sharing problem with WebUI

[jw3193]

I'm having an issue with document sharing in 4.5.4NE. I have a user who shared his notebook with me, and all appeared to work fine. I can browse the book and see the names of pages just fine. The problem is that when I click on them, there's no content. If I view this notebook directly in my browser (not using the Zimbra WebUI), I can see the content just fine. Has anyone seen this issue before?

Thanks, Justin.