Well your dash is up to date. So thats ok. Did you delete the default.xbe?
OK lets back up. You do have a file in the root of C: named "xboxdash.xbe" (spelled just like that)?
Now in your "evox.ini" is also says "MSDashBoard = "c:\xboxdash.xbe" (spelled just like that)?
What we know is, Evox can launch MS Dash from within Evox. So we know the xboxdash.xbe is good or it wouldn't be able to launch it. Xbox can't seem to locate this file for some reason when we ask the xbox to launch it. Are you using a softmod or modchip?
Please answer the top two questions and the bottom question.
Also, do you know if the eject button ever did work correctly (boot the MS dash)?