Just an FYI, I have commented in a few places on my blog but in case you missed it.  If you have the second update of the attachment viewer and are running on the Mac you can uninstall and then reinstall the Widget to get it working again.  You need to actually uninstall the widget from My Widgets and then drag the bitmap below (which points to the extension.xml) back on to the My Widgets panel.

Sorry for the inconvenience.