Well, one thing to be aware of is that some manufacturers number MIDI messages starting at 0 and others starting at 1.  So, it could be that you're dealing with an off by one error.

If that isn't the issue, if I were you, I'd connect the Switch Doctor to a computer to double check what values it is sending.  On Mac I'd use MIDI Monitor, and on Windows I'd use MIDI Ox.  They're both free apps…