If you can view object attributes (e.g object_name), then its a problem with you taskspace viewer configuration for those image types.
"...if the user selects to view a document and there is no viewer configured for the document file type."
As I said in my previous post, you need to configure viewer for various format types (e.g. pdf, tiff, gif, etc).
You need to map Viewer for each format type b/c different apps can open different file types, so Taskspace allows you to configure whatever app you want to open file type.
Yes, but your question also mentioned doc, jpeg, and tiff. Acrobat wont be able to read these file formats, so you need to pick another viewer.