I wonder if the WRAP lockups with the cover on are due to the screws
holding the cover on hitting a trace on the board and changing a
signal level just enough that over time something builds up and hangs
the system?  

My WRAP board (recently bought) has the cover one and it's works
great.  Though I do have an extra hole in the case since I drilled the
first one in the wrong spot for the wireless antenna...

John