diff --git a/docs/change-log.md b/docs/change-log.md
index c32a8b7c..7347af50 100644
--- a/docs/change-log.md
+++ b/docs/change-log.md
@@ -13,6 +13,7 @@
 
 -	gracefully degrade on IE exceptions when setting invalid values
 -	fixes for Typescript definition file
+-	fixed bug in keys algorithm when mixing keyed and unkeyed elements [#246](https://github.com/lhorie/mithril.js/issues/246)
 
 ---
 
diff --git a/docs/components.md b/docs/components.md
index 712cfe5e..bb73900f 100644
--- a/docs/components.md
+++ b/docs/components.md
@@ -99,7 +99,7 @@ autocompleter.controller = function(data, getter) {
     this.change = function(value) {
         this.value(value);
 
-        var list = value === "" ? [] : data.filter(function(item) {
+        var list = value === "" ? [] : data().filter(function(item) {
             return this.getter(item).toLowerCase().indexOf(value.toLowerCase()) > -1;
         }, this);
         this.data(list);
@@ -130,7 +130,7 @@ var dashboard = {}
 
 dashboard.controller = function() {
     this.names = m.prop([{id: 1, name: "John"}, {id: 2, name: "Bob"}, {id: 2, name: "Mary"}]);
-    this.autocompleter = new autocompleter.controller(this.names(), function(item) {
+    this.autocompleter = new autocompleter.controller(this.names, function(item) {
         return item.name;
     });
 };
diff --git a/docs/mithril.deferred.md b/docs/mithril.deferred.md
index 8f07ed19..00e5196a 100644
--- a/docs/mithril.deferred.md
+++ b/docs/mithril.deferred.md
@@ -119,7 +119,7 @@ var greetAsync = function() {
 
 ### Differences from Promises/A+
 
-For the most part, Mithril promises behave as you'd expect a [Promise/A+](http://promises-aplus.github.io/promises-spec/) promise to behave, but they have a few differences.
+For the most part, Mithril promises behave as you'd expect a [Promise/A+](http://promises-aplus.github.io/promises-spec/) promise to behave, but have one difference: Mithril promises attempt to execute synchronously if possible.
 
 #### Synchronous execution
 
diff --git a/mithril.js b/mithril.js
index 40064b93..93f8f375 100644
--- a/mithril.js
+++ b/mithril.js
@@ -118,7 +118,7 @@ Mithril = m = new function app(window, undefined) {
 							if (!existing[key]) existing[key] = {action: INSERTION, index: i}
 							else existing[key] = {action: MOVE, index: i, from: existing[key].index, element: parentElement.childNodes[existing[key].index]}
 						}
-						else unkeyed.push({index: i, element: parentElement.childNodes[i]})
+						else unkeyed.push({index: i, element: parentElement.childNodes[i] || window.document.createElement("div")})
 					}
 				}
 				var actions = Object.keys(existing).map(function(key) {return existing[key]})
diff --git a/tests/mithril-tests.js b/tests/mithril-tests.js
index b3560c79..9c9f95cd 100644
--- a/tests/mithril-tests.js
+++ b/tests/mithril-tests.js
@@ -584,6 +584,17 @@ function testMithril(mock) {
 		var fifthAfter = root.childNodes[1]
 		return firstBefore === firstAfter && secondBefore === secondAfter && thirdBefore === thirdAfter && fourthBefore === fourthAfter && fifthBefore === fifthAfter
 	})
+	test(function() {
+		//https://github.com/lhorie/mithril.js/issues/246
+		//insert at beginning with non-keyed in the middle
+		var root = mock.document.createElement("div")
+		m.render(root, [m("a", {key: 1})])
+		var firstBefore = root.childNodes[0]
+		m.render(root, [m("a", {key: 2}), m("br"), m("a", {key: 1})])
+		var firstAfter = root.childNodes[2]
+		console.log(root.childNodes)
+		return firstBefore == firstAfter && root.childNodes[0].key == 2 && root.childNodes.length == 3
+	})
 	test(function() {
 		//https://github.com/lhorie/mithril.js/issues/134
 		var root = mock.document.createElement("div")
diff --git a/tests/mock.js b/tests/mock.js
index fae3574e..660f08f4 100644
--- a/tests/mock.js
+++ b/tests/mock.js
@@ -15,7 +15,11 @@ mock.window = new function() {
 			insertBefore: function(node, reference) {
 				node.parentNode = this
 				var referenceIndex = this.childNodes.indexOf(reference)
-				if (referenceIndex < 0) this.childNodes.push(node)
+				if (referenceIndex < 0) {
+					var index = this.childNodes.indexOf(node)
+					if (index > -1) this.childNodes.splice(index, 1) 
+					this.childNodes.push(node)
+				}
 				else {
 					var index = this.childNodes.indexOf(node)
 					if (index > -1) this.childNodes.splice(index, 1)