Try editing your evox.ini file where it says MS Dashboard so it looks like this:
MSDashBoard = "c:\xboxdash.xbe"
just ftp into your xbox and check to make sure that is the name of your other dash, you should have an evoxdash.xbe and there should be another .xbe file in your c: directory. It will probably be xboxdash.xbe or msdash.xbe just change the line of code above to the file you find. Hope this helps.