Viewer pane and .doc and .xls files

Since you're using Open Office it's probably easiest to:

[ol][li]Install the Open Office ActiveX control, as described under How to view Open Office documents at the top of the ActiveX plugin thread.


[/li]
[li]Turn off the Microsoft Office line in the ActiveX plugin's configuration (to prevent the Microsoft viewers getting in the way or slowing things down, if they are not working currently).


[/li]
[li]Finally, add the MS Office file extensions to the Internet Explorer line in the ActiveX plugin's configuration. (This is because Open Office's ActiveX control will give IE the ability to show those file formats, and so Opus can use an embedded IE window to show them.)[/li][/ol]

It's possible that .doc files are like .pdf files where you only get a thumbnail if one was saved into. Either way, you should see the same thing in Explorer as there's no code in Opus itself to generate .doc thumbnails. When Opus doesn't have its own code to generate a thumbnail it will ask 3rd party components which have plugged themselves into the Shell (Windows Explorer).