Index: test/unit/event.js
===================================================================
--- test/unit/event.js	(revision 5742)
+++ test/unit/event.js	(working copy)
@@ -11,6 +11,36 @@
 	ok( !jQuery.data(jQuery("#firstp")[0], "events"), "Event handler unbound when using data." );
 });
 
+test("bind()/unbind(), with same handler but different data", function() {
+	expect(3);
+	var data1 = 0, data2 = 0;
+	var handler = function(event) {
+		if (event.data.foo)
+			data1++;
+		if (event.data.bar)
+			data2++;
+	};
+	jQuery("#firstp").bind("click", {foo: "bar"}, handler);//.click().unbind("click", handler);
+	jQuery("#simon1").bind("click", {foo: "bar"}, handler);//.click().unbind("click", handler);
+	jQuery("#simon1").bind("click", {foo: "bar"}, handler);//.click().unbind("click", handler);
+	jQuery("#simon1").bind("click", {bar: "foo"}, handler);//.click().unbind("click", handler);
+	jQuery("#simon1").bind("click", {bar: "foo"}, handler);//.click().unbind("click", handler);
+	jQuery("#firstp").bind("click", {bar: "foo"}, handler);//.click().unbind("click", handler);
+	jQuery("#firstp").bind("click", {foo: "bar"}, handler);//.click().unbind("click", handler);
+	jQuery("#firstp").bind("click", {bar: "foo"}, handler);//.click().unbind("click", handler);
+
+	jQuery("#firstp").click();
+	jQuery("#simon1").click();
+	jQuery("#foo").click();
+
+	ok( data1==4 && data2==4, "Event handler was bound two times with different data");
+
+	jQuery("#firstp").unbind("click", handler);
+	jQuery("#simon1").unbind("click", handler);
+	ok( !jQuery.data(jQuery("#firstp")[0], "events"), "Event handler unbound when using different data but same handler. (1)" );
+	ok( !jQuery.data(jQuery("#simon1")[0], "events"), "Event handler unbound when using different data but same handler. (2)" );
+});
+
 test("bind(), with data, trigger with data", function() {
 	expect(4);
 	var handler = function(event, data) {
Index: src/event.js
===================================================================
--- src/event.js	(revision 5742)
+++ src/event.js	(working copy)
@@ -48,6 +48,8 @@
 		// event in IE.
 		handle.elem = elem;
 
+		var guid = this.guid;
+
 		// Handle multiple events separated by a space
 		// jQuery(...).bind("mouseover mouseout", fn);
 		jQuery.each(types.split(/\s+/), function(index, type) {
@@ -75,13 +77,36 @@
 				}
 			}
 
-			// Add the function to the element's handler list
-			handlers[handler.guid] = handler;
+			// handler with same guid is already bound. If this
+			// bind contains data, add the handler again with
+			// another guid.
+			if (handlers[handler.guid] && data) {
+				// add reference to other handlers for
+                                // unbinding
+				if (handlers[handler.guid].prev)
+					// handler has already a reference, put
+					// the new one in between
+					handler.prev = handlers[fn.guid].prev;
+				else
+					handler.prev = handler.guid;
 
+				handler.guid = guid++;
+				handlers[handler.guid] = handler;
+
+				// making a cycling reference from one event to
+				// eachother to be able to start at any event
+				// when unbinding
+				handlers[fn.guid].prev = handler.guid;
+			}
+			else 
+				handlers[handler.guid] = handler;
+
 			// Keep track of which events have been used, for global triggering
 			jQuery.event.global[type] = true;
 		});
 
+		this.guid = guid;
+
 		// Nullify elem to prevent memory leaks in IE
 		elem = null;
 	},
@@ -118,9 +143,19 @@
 
 					if ( events[type] ) {
 						// remove the given handler for the given type
-						if ( handler )
+						if ( handler ) {
+							//same handler was bound several times
+							//with different data
+							//var prev = events[type][handler.prev];
+							var prev = events[type][events[type][handler.guid].prev];
 							delete events[type][handler.guid];
 
+							while (prev) {
+								handler = prev;
+								prev = events[type][handler.prev];
+								delete events[type][handler.guid];
+							}
+						}
 						// remove all handlers for the given type
 						else
 							for ( handler in events[type] )