default.xip found in "C:\" for the first MSDash or in "C:\xboxdashdata.xxxxxxx";
mainmenu5.xip found in the same location.
sound files found in "C:\Audio"
The specific image files are cellwall.xbx, xboxlogo.xbx (standard screen) or xboxlogow.xbx for widescreen, xbox4.xbx (the Orb).
Can you try navigating to "C:\xboxdashdata.xxxxxxx", find default.xip or mainmenu5.xip, then press "A". Check if it can be opened properly. Then, try extracting those files and select them from file manager one at a time and see if ImageViewer can display it.
I wonder what's wrong with Xbox Live 2.0.
What games contain the files for XBL 2.0 so I may check them out myself? I only need those two files.