changes:

- changed the variables from keypad to reprapworld_keypad
- added a missing ifdef check

Marlin/Configuration.h

 // ==> REMEMBER TO INSTALL U8glib to your ARDUINO library folder: http://code.google.com/p/u8glib/wiki/u8glib
 //#define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
 
-// The RepRapWorld Keypad v1.1
+// The RepRapWorld REPRAPWORLD_KEYPAD v1.1
 // http://reprapworld.com/?products_details&products_id=202&cPath=1591_1626
-//#define KEYPAD
-//#define KEYPAD_MOVE_STEP 10.0 // how much should be moved when a key is pressed, eg 10.0 means 10mm per click
+//#define REPRAPWORLD_KEYPAD
+//#define REPRAPWORLD_KEYPAD_MOVE_STEP 10.0 // how much should be moved when a key is pressed, eg 10.0 means 10mm per click
 
 //automatic expansion
 #if defined (REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER)
  #define NEWPANEL
 #endif 
 
-#if defined(KEYPAD)
+#if defined(REPRAPWORLD_KEYPAD)
   #define NEWPANEL
   #define ULTIPANEL
 #endif

Marlin/pins.h

       #define BEEPER 33	 // Beeper on AUX-4
 
       //buttons are directly attached using AUX-2
-      #ifdef KEYPAD
+      #ifdef REPRAPWORLD_KEYPAD
         #define BTN_EN1 64 // encoder
         #define BTN_EN2 59 // encoder
         #define BTN_ENC 63 // enter button
         #define SHIFT_CLK 44 // shift register
         #define SHIFT_LD 42 // shift register
         // define register bit values, don't change it
-        #define BLEN_KEYPAD_F3 0
-        #define BLEN_KEYPAD_F2 1
-        #define BLEN_KEYPAD_F1 2
-        #define BLEN_KEYPAD_UP 3
-        #define BLEN_KEYPAD_RIGHT 4
-        #define BLEN_KEYPAD_MIDDLE 5
-        #define BLEN_KEYPAD_DOWN 6
-        #define BLEN_KEYPAD_LEFT 7
+        #define BLEN_REPRAPWORLD_KEYPAD_F3 0
+        #define BLEN_REPRAPWORLD_KEYPAD_F2 1
+        #define BLEN_REPRAPWORLD_KEYPAD_F1 2
+        #define BLEN_REPRAPWORLD_KEYPAD_UP 3
+        #define BLEN_REPRAPWORLD_KEYPAD_RIGHT 4
+        #define BLEN_REPRAPWORLD_KEYPAD_MIDDLE 5
+        #define BLEN_REPRAPWORLD_KEYPAD_DOWN 6
+        #define BLEN_REPRAPWORLD_KEYPAD_LEFT 7
 	  #else
         #define BTN_EN1 37
         #define BTN_EN2 35

Marlin/ultralcd.cpp

 
 /** Used variables to keep track of the menu */
 volatile uint8_t buttons;//Contains the bits of the currently pressed buttons.
-volatile uint8_t buttons_keypad; // to store the keypad shiftregister values
+volatile uint8_t buttons_reprapworld_keypad; // to store the reprapworld_keypad shiftregister values
 
 uint8_t currentMenuViewOffset;              /* scroll offset in the current menu */
 uint32_t blocking_enc;
 menu_edit_type(float, float52, ftostr52, 100)
 menu_edit_type(unsigned long, long5, ftostr5, 0.01)
 
-#ifdef KEYPAD
-	static void keypad_move_y_down() {
-	SERIAL_ECHO("keypad_move_y_down");
+#ifdef REPRAPWORLD_KEYPAD
+	static void reprapworld_keypad_move_y_down() {
         encoderPosition = 1;
-        move_menu_scale = KEYPAD_MOVE_STEP;
+        move_menu_scale = REPRAPWORLD_KEYPAD_MOVE_STEP;
 		lcd_move_y();
 	}
-	static void keypad_move_y_up() {
+	static void reprapworld_keypad_move_y_up() {
 		encoderPosition = -1;
-		move_menu_scale = KEYPAD_MOVE_STEP;
+		move_menu_scale = REPRAPWORLD_KEYPAD_MOVE_STEP;
     	lcd_move_y();
 	}
-	static void keypad_move_home() {
+	static void reprapworld_keypad_move_home() {
 		//enquecommand_P((PSTR("G28"))); // move all axis home
 		// TODO gregor: move all axis home, i have currently only one axis on my prusa i3
 		enquecommand_P((PSTR("G28 Y")));
     WRITE(BTN_EN1,HIGH);
     WRITE(BTN_EN2,HIGH);
     WRITE(BTN_ENC,HIGH);
-    #ifdef KEYPAD
+    #ifdef REPRAPWORLD_KEYPAD
       pinMode(SHIFT_CLK,OUTPUT);
       pinMode(SHIFT_LD,OUTPUT);
       pinMode(SHIFT_OUT,INPUT);
     if (lcd_next_update_millis < millis())
     {
 #ifdef ULTIPANEL
-		#ifdef KEYPAD
-        	if (KEYPAD_MOVE_Y_DOWN) {
-        		keypad_move_y_down();
+		#ifdef REPRAPWORLD_KEYPAD
+        	if (REPRAPWORLD_KEYPAD_MOVE_Y_DOWN) {
+        		reprapworld_keypad_move_y_down();
         	}
-        	if (KEYPAD_MOVE_Y_UP) {
-        		keypad_move_y_up();
+        	if (REPRAPWORLD_KEYPAD_MOVE_Y_UP) {
+        		reprapworld_keypad_move_y_up();
         	}
-        	if (KEYPAD_MOVE_HOME) {
-        		keypad_move_home();
+        	if (REPRAPWORLD_KEYPAD_MOVE_HOME) {
+        		reprapworld_keypad_move_home();
         	}
 		#endif
         if (encoderDiff)
     if((blocking_enc<millis()) && (READ(BTN_ENC)==0))
         newbutton |= EN_C;
     buttons = newbutton;
-    // for the keypad
-    uint8_t newbutton_keypad=0;
-    WRITE(SHIFT_LD,LOW);
-    WRITE(SHIFT_LD,HIGH);
-    for(int8_t i=0;i<8;i++) {
-        newbutton_keypad = newbutton_keypad>>1;
-        if(READ(SHIFT_OUT))
-            newbutton_keypad|=(1<<7);
-        WRITE(SHIFT_CLK,HIGH);
-        WRITE(SHIFT_CLK,LOW);
-    }
-    buttons_keypad=~newbutton_keypad; //invert it, because a pressed switch produces a logical 0
+    #ifdef REPRAPWORLD_KEYPAD
+      // for the reprapworld_keypad
+      uint8_t newbutton_reprapworld_keypad=0;
+      WRITE(SHIFT_LD,LOW);
+      WRITE(SHIFT_LD,HIGH);
+      for(int8_t i=0;i<8;i++) {
+          newbutton_reprapworld_keypad = newbutton_reprapworld_keypad>>1;
+          if(READ(SHIFT_OUT))
+              newbutton_reprapworld_keypad|=(1<<7);
+          WRITE(SHIFT_CLK,HIGH);
+          WRITE(SHIFT_CLK,LOW);
+      }
+      buttons_reprapworld_keypad=~newbutton_reprapworld_keypad; //invert it, because a pressed switch produces a logical 0
+	#endif
 #else   //read it from the shift register
     uint8_t newbutton=0;
     WRITE(SHIFT_LD,LOW);

Marlin/ultralcd.h

   #ifdef ULTIPANEL
   void lcd_buttons_update();
   extern volatile uint8_t buttons;  //the last checked buttons in a bit array.
-  #ifdef KEYPAD
-    extern volatile uint8_t buttons_keypad; // to store the keypad shiftregister values
+  #ifdef REPRAPWORLD_KEYPAD
+    extern volatile uint8_t buttons_reprapworld_keypad; // to store the keypad shiftregister values
   #endif
   #else
   FORCE_INLINE void lcd_buttons_update() {}
     #define EN_A (1<<BLEN_A)
 
     #define LCD_CLICKED (buttons&EN_C)
-    #ifdef KEYPAD
-  	  #define EN_KEYPAD_F3 (1<<BLEN_KEYPAD_F3)
-  	  #define EN_KEYPAD_F2 (1<<BLEN_KEYPAD_F2)
-  	  #define EN_KEYPAD_F1 (1<<BLEN_KEYPAD_F1)
-  	  #define EN_KEYPAD_UP (1<<BLEN_KEYPAD_UP)
-  	  #define EN_KEYPAD_RIGHT (1<<BLEN_KEYPAD_RIGHT)
-  	  #define EN_KEYPAD_MIDDLE (1<<BLEN_KEYPAD_MIDDLE)
-  	  #define EN_KEYPAD_DOWN (1<<BLEN_KEYPAD_DOWN)
-  	  #define EN_KEYPAD_LEFT (1<<BLEN_KEYPAD_LEFT)
+    #ifdef REPRAPWORLD_KEYPAD
+  	  #define EN_REPRAPWORLD_KEYPAD_F3 (1<<BLEN_REPRAPWORLD_KEYPAD_F3)
+  	  #define EN_REPRAPWORLD_KEYPAD_F2 (1<<BLEN_REPRAPWORLD_KEYPAD_F2)
+  	  #define EN_REPRAPWORLD_KEYPAD_F1 (1<<BLEN_REPRAPWORLD_KEYPAD_F1)
+  	  #define EN_REPRAPWORLD_KEYPAD_UP (1<<BLEN_REPRAPWORLD_KEYPAD_UP)
+  	  #define EN_REPRAPWORLD_KEYPAD_RIGHT (1<<BLEN_REPRAPWORLD_KEYPAD_RIGHT)
+  	  #define EN_REPRAPWORLD_KEYPAD_MIDDLE (1<<BLEN_REPRAPWORLD_KEYPAD_MIDDLE)
+  	  #define EN_REPRAPWORLD_KEYPAD_DOWN (1<<BLEN_REPRAPWORLD_KEYPAD_DOWN)
+  	  #define EN_REPRAPWORLD_KEYPAD_LEFT (1<<BLEN_REPRAPWORLD_KEYPAD_LEFT)
 
-  	  #define LCD_CLICKED ((buttons&EN_C) || (buttons_keypad&EN_KEYPAD_F1))
-  	  #define KEYPAD_MOVE_Y_DOWN (buttons_keypad&EN_KEYPAD_DOWN)
-  	  #define KEYPAD_MOVE_Y_UP (buttons_keypad&EN_KEYPAD_UP)
-  	  #define KEYPAD_MOVE_HOME (buttons_keypad&EN_KEYPAD_MIDDLE)
-    #endif //KEYPAD
+  	  #define LCD_CLICKED ((buttons&EN_C) || (buttons_reprapworld_keypad&EN_REPRAPWORLD_KEYPAD_F1))
+  	  #define REPRAPWORLD_KEYPAD_MOVE_Y_DOWN (buttons_reprapworld_keypad&EN_REPRAPWORLD_KEYPAD_DOWN)
+  	  #define REPRAPWORLD_KEYPAD_MOVE_Y_UP (buttons_reprapworld_keypad&EN_REPRAPWORLD_KEYPAD_UP)
+  	  #define REPRAPWORLD_KEYPAD_MOVE_HOME (buttons_reprapworld_keypad&EN_REPRAPWORLD_KEYPAD_MIDDLE)
+    #endif //REPRAPWORLD_KEYPAD
   #else
     //atomatic, do not change
     #define B_LE (1<<BL_LE)