diff --git a/teensy/teensy-keyboard.cpp b/teensy/teensy-keyboard.cpp
index a946525..96b83f9 100644
--- a/teensy/teensy-keyboard.cpp
+++ b/teensy/teensy-keyboard.cpp
@@ -33,18 +33,23 @@ uint8_t kbEventCount = 0;
 uint8_t kbEventHead = 0;
 uint8_t kbEventPtr = 0;
 
-bool addEvent(uint8_t kc, bool pressed)
+bool TeensyKeyboard::addEvent(uint8_t kc, bool pressed)
 {
   if (kbEventCount >= MAXKBEVENTS)
     return false;
 
+  if (pressed && kbEventCount+numPressed >= MAXKBEVENTS) {
+    // save space in the event queue for any keyup events that may come
+    return false;
+  }
+
   keyboardEvents[kbEventPtr].keycode = kc;
   keyboardEvents[kbEventPtr++].pressedIfTrue = pressed;
   if (kbEventPtr >= MAXKBEVENTS) kbEventPtr = 0;
   kbEventCount++;
 }
 
-bool popEvent(uint8_t *kc, bool *pressed)
+bool TeensyKeyboard::popEvent(uint8_t *kc, bool *pressed)
 {
   if (kbEventCount) {
     *kc = keyboardEvents[kbEventHead].keycode;
@@ -258,12 +263,8 @@ void TeensyKeyboard::maintainKeyboard()
     bool pressed;
     if (popEvent(&kc, &pressed)) {
       if (pressed) {
-	sprintf(debugBuf, "%d press  ", kc);
-	g_display->debugMsg(debugBuf);
 	vmkeyboard->keyDepressed(kc);
       } else {
-	sprintf(debugBuf, "%d relsd  ", kc);
-	g_display->debugMsg(debugBuf);
 	vmkeyboard->keyReleased(kc);
       }
     }
diff --git a/teensy/teensy-keyboard.h b/teensy/teensy-keyboard.h
index 2e07846..6f2e042 100644
--- a/teensy/teensy-keyboard.h
+++ b/teensy/teensy-keyboard.h
@@ -21,6 +21,10 @@ class TeensyKeyboard : public PhysicalKeyboard {
   void pressedKey(uint8_t key);
   void releasedKey(uint8_t key);
 
+private:
+  bool addEvent(uint8_t kc, bool pressed);
+  bool popEvent(uint8_t *kc, bool *pressed);
+
  private:
   bool leftShiftPressed;
   bool rightShiftPressed;
diff --git a/teensy/teensy.ino b/teensy/teensy.ino
index f37eb74..9cc673a 100644
--- a/teensy/teensy.ino
+++ b/teensy/teensy.ino
@@ -124,20 +124,34 @@ static uint8_t usb_scanmap[256] = {
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 240-249
   0, 0, 0, 0, 0, 0 // 250-255
 };
-  
+	
+uint8_t keysPressed[256]; // FIXME: if we need to save RAM, make this bitflags
+
 void onKeypress(uint8_t keycode)
 {
+  if (keysPressed[keycode])
+    return; // defeat auto-repeat
+  if (!usb_scanmap[keycode])
+    return; // skip undefined keys
+
   if (keycode == 67 || keycode == 70) {
     // F10 or PrtSc/SysRq are interrupt buttons. Probably needs to be
     // configurable somehow...
     g_biosInterrupt = true;
   } else {
+    keysPressed[keycode] = 1;
     ((TeensyKeyboard *)g_keyboard)->pressedKey(usb_scanmap[keycode]);
   }
 }
 
 void onKeyrelease(uint8_t keycode)
 {
+  if (!keysPressed[keycode])
+    return; // defeat auto-repeat
+  if (!usb_scanmap[keycode])
+    return; // skip undefined keys
+
+  keysPressed[keycode] = 0;
   ((TeensyKeyboard *)g_keyboard)->releasedKey(usb_scanmap[keycode]);
 }
 
@@ -160,6 +174,7 @@ void setup()
 //  enableFaultHandler();
 //  SCB_SHCSR |= SCB_SHCSR_BUSFAULTENA | SCB_SHCSR_USGFAULTENA | SCB_SHCSR_MEMFAULTENA;
 
+  memset(keysPressed, 0, sizeof(keysPressed));
 
   // set the Time library to use Teensy 3.0's RTC to keep time
   setSyncProvider(getTeensy3Time);