stuck programming my teensyduino buttonmasher

hi there,
I'm working on a project with 16 arcadebuttons, they have to trigger note on and note off messages. I've done some programming and it works the way i want it to work, except for button 6, soldered to pin 10. I've tried some other pins but no succes... Can someone see a mistake in my coding? By default there was a button 0, is that of any importance? Any help would be appreciated!

greetings, patrick

/* Buttons to USB MIDI Example

   You must select MIDI from the "Tools > USB Type" menu

   This example code is in the public domain.
*/

#include <Bounce.h>

// the MIDI channel number to send messages
const int channel = 13;

// Create Bounce objects for each button.  The Bounce object
// automatically deals with contact chatter or "bounce", and
// it makes detecting changes very simple.
Bounce button1 = Bounce(1, 8);  // 5 = 5 ms debounce time
Bounce button2 = Bounce(2, 8);  // which is appropriate for good
Bounce button3 = Bounce(3, 8);  // quality mechanical pushbuttons
Bounce button4 = Bounce(4, 8);
Bounce button5 = Bounce(5, 8);  // if a button is too "sensitive"
Bounce button6 = Bounce(6, 8);  // to rapid touch, you can
Bounce button7 = Bounce(7, 8);  // increase this time.
Bounce button8 = Bounce(8, 8);
Bounce button9 = Bounce(9, 8);
Bounce button10 = Bounce(10, 8);
Bounce button11 = Bounce(11, 8);
Bounce button12 = Bounce(12, 8);
Bounce button13 = Bounce(13, 8);
Bounce button14 = Bounce(14, 8);
Bounce button15 = Bounce(15, 8);
Bounce button16 = Bounce(16, 8);

void setup() {
  // Configure the pins for input mode with pullup resistors.
  // The pushbuttons connect from each pin to ground.  When
  // the button is pressed, the pin reads LOW because the button
  // shorts it to ground.  When released, the pin reads HIGH
  // because the pullup resistor connects to +5 volts inside
  // the chip.  LOW for "on", and HIGH for "off" may seem
  // backwards, but using the on-chip pullup resistors is very
  // convenient.  The scheme is called "active low", and it's
  // very commonly used in electronics... so much that the chip
  // has built-in pullup resistors!
  pinMode(4, INPUT_PULLUP);
  pinMode(5, INPUT_PULLUP);
  pinMode(7, INPUT_PULLUP);
  pinMode(8, INPUT_PULLUP);
  pinMode(9, INPUT_PULLUP);
  pinMode(10, INPUT_PULLUP);
  pinMode(11, INPUT_PULLUP);  // Teensy++ LED, may need 1k resistor pullup
  pinMode(12, INPUT_PULLUP);
  pinMode(13, INPUT_PULLUP);
  pinMode(0, INPUT_PULLUP);
  pinMode(1, INPUT_PULLUP);
  pinMode(2, INPUT_PULLUP);
  pinMode(3, INPUT_PULLUP);
  pinMode(14, INPUT_PULLUP);
  pinMode(15, INPUT_PULLUP);
  pinMode(16, INPUT_PULLUP); 
}

void loop() {
  // Update all the buttons.  There should not be any long
  // delays in loop(), so this runs repetitively at a rate
  // faster than the buttons could be pressed and released.

  button1.update();
  button2.update();
  button3.update();
  button4.update();
  button5.update();
  button6.update();
  button7.update();
  button8.update();
  button9.update();
  button10.update();
  button11.update();
  button12.update();
  button13.update();
  button14.update();
  button15.update();  
  button16.update();


  // Check each button for "falling" edge.
  // Send a MIDI Note On message when each button presses
  // Update the Joystick buttons only upon changes.
  // falling = high (not pressed - voltage from pullup resistor)
  //           to low (pressed - button connects pin to ground)

  if (button1.fallingEdge()) {
    usbMIDI.sendNoteOn(48, 99, channel);  // 61 = C#4
  }
  if (button2.fallingEdge()) {
    usbMIDI.sendNoteOn(49, 99, channel);  // 62 = D4
  }
  if (button3.fallingEdge()) {
    usbMIDI.sendNoteOn(50, 99, channel);  // 63 = D#4
  }
  if (button4.fallingEdge()) {
    usbMIDI.sendNoteOn(51, 99, channel);  // 64 = E4
  }
  if (button5.fallingEdge()) {
    usbMIDI.sendNoteOn(44, 99, channel);  // 65 = F4
  }
  if (button6.fallingEdge()) {
    usbMIDI.sendNoteOn(45, 99, channel);  // 66 = F#4
  }
  if (button7.fallingEdge()) {
    usbMIDI.sendNoteOn(46, 99, channel);  // 67 = G4
  }
  if (button8.fallingEdge()) {
    usbMIDI.sendNoteOn(47, 99, channel);  // 68 = G#4
  }
  if (button9.fallingEdge()) {
    usbMIDI.sendNoteOn(40, 99, channel);  // 69 = A5
  }
  if (button10.fallingEdge()) {
    usbMIDI.sendNoteOn(41, 99, channel);  // 70 = A#5
  }
  if (button11.fallingEdge()) {
    usbMIDI.sendNoteOn(42, 99, channel);  // 71 = B5
  }
  if (button12.fallingEdge()) {
    usbMIDI.sendNoteOn(43, 99, channel);  // 71 = B5
  }
  if (button13.fallingEdge()) {
    usbMIDI.sendNoteOn(36, 99, channel);  // 71 = B5
  }
  if (button14.fallingEdge()) {
    usbMIDI.sendNoteOn(37, 99, channel);  // 71 = B5
  }
  if (button15.fallingEdge()) {
    usbMIDI.sendNoteOn(38, 99, channel);  // 71 = B5
  }
  if (button16.fallingEdge()) {
    usbMIDI.sendNoteOn(39, 99, channel);  // 71 = B5
  }

 
 
  if (button1.risingEdge()) {
    usbMIDI.sendNoteOff(48, 0, channel);  // 61 = C#4
  }
  if (button2.risingEdge()) {
    usbMIDI.sendNoteOff(49, 0, channel);  // 62 = D4
  }
  if (button3.risingEdge()) {
    usbMIDI.sendNoteOff(50, 0, channel);  // 63 = D#4
  }
  if (button4.risingEdge()) {
    usbMIDI.sendNoteOff(51, 0, channel);  // 64 = E4
  }
  if (button5.risingEdge()) {
    usbMIDI.sendNoteOff(44, 0, channel);  // 65 = F4
  }
  if (button6.risingEdge()) {
    usbMIDI.sendNoteOff(45, 0, channel);  // 66 = F#4
  }
  if (button7.risingEdge()) {
    usbMIDI.sendNoteOff(46, 0, channel);  // 67 = G4
  }
  if (button8.risingEdge()) {
    usbMIDI.sendNoteOff(47, 0, channel);  // 68 = G#4
  }
  if (button9.risingEdge()) {
    usbMIDI.sendNoteOff(40, 0, channel);  // 69 = A5
  }
  if (button10.risingEdge()) {
    usbMIDI.sendNoteOff(41, 0, channel);  // 70 = A#5
  }
  if (button11.risingEdge()) {
    usbMIDI.sendNoteOff(42, 0, channel);  // 71 = B5
  }
  if (button12.risingEdge()) {
    usbMIDI.sendNoteOff(43, 0, channel);  // 71 = B5
  }
  if (button13.risingEdge()) {
    usbMIDI.sendNoteOff(36, 0, channel);  // 71 = B5
  }
  if (button14.risingEdge()) {
    usbMIDI.sendNoteOff(37, 0, channel);  // 71 = B5
  }
  if (button15.risingEdge()) {
    usbMIDI.sendNoteOff(38, 0, channel);  // 71 = B5
  }
  if (button16.risingEdge()) {
    usbMIDI.sendNoteOff(39, 0, channel);  // 71 = B5
  }
}

I see, "Bounce buttonX = Bounce( X, 8 );" for X = 1 through 16, and "pinMode(Y, INPUT_PULLUP)" for Y = 0 through 5, and 7 through 16. The arguments to both of those functions look to be pin numbers. I'm not familiar with your hardware, but, intuitively, I'd expect those two lists of pins to be the same.

Bounce button1 = Bounce(1, 8);  // 5 = 5 ms debounce time
Bounce button2 = Bounce(2, 8);  // which is appropriate for good
Bounce button3 = Bounce(3, 8);  // quality mechanical pushbuttons
Bounce button4 = Bounce(4, 8);
Bounce button5 = Bounce(5, 8);  // if a button is too "sensitive"
Bounce button6 = Bounce(6, 8);  // to rapid touch, you can
Bounce button7 = Bounce(7, 8);  // increase this time.
Bounce button8 = Bounce(8, 8);
Bounce button9 = Bounce(9, 8);
Bounce button10 = Bounce(10, 8);
Bounce button11 = Bounce(11, 8);
Bounce button12 = Bounce(12, 8);
Bounce button13 = Bounce(13, 8);
Bounce button14 = Bounce(14, 8);
Bounce button15 = Bounce(15, 8);
Bounce button16 = Bounce(16, 8);

You got something against arrays? for loops?

problem solved, thanks tmd!