Dave Smith Instruments SYNTHESIZERS

Hi,
I'm new to this list, I just got Evolver #3238 (ver 3.0) last week, to
add some real analogue to my arsenal.  I have started reading the
archives & I'm also working thru the forum at EX5Tech.  I'm mainly a
guitarist but I like to program funny noises too.  I started with
synths way back in the day with a Korg Poly 6, added the rack mount
Korg EX 800, went through a Juno 106, & then to a DX7.  My current
setup is very Dave, I am using a Wavestation EX MIDIed to the Evolver.

Since I am not real fluent in MIDI, CC messages & such, & there is one
bit of weirdness I can't figure out, here is my question for you. 
I have a momentary footswitch set up as an Effects Switch (Assignable
Pedal/Switch 1) on the Wavestation.  If it is sending CC it is #4,
which is not listed as received in the Evolver's manual.  When I press
the footswitch, the Evolver distortion is cranked up to 99.  I also
tried an Expression Pedal instead of the momentary switch, and pressed
1/2 way down, the distortion again switches from 0 to 99.  Distortion
is CC # 12, but according to the Wavestation's manual, it only sends
CC #s 1, 4, 6, 7, 15, 17, 38, 64, 100 & 101 (most of which sadly the
EVO does not receive).  And this is not really continuous control
either since the dist. goes from 0 straight to 99. 
What is happening ???  

thanks for any advice you can give
regards 
Harold Land