So that eliminates the dongle as an issue, its as simple a config as it gets.
I'd give the board a good look, as noted above...when you say some channels work and others don't, is it consistent? Or is it intermittent behavior on all channels?
I've got limited experience with the MR-16, no longer have one, so others more familiar with the board will hopefully chime in. Its not a complex board, by any means.