diff --git a/src/effects.js b/src/effects.js
index ff2f145b8..7fa734208 100644
--- a/src/effects.js
+++ b/src/effects.js
@@ -13,7 +13,7 @@ var elemdisplay = {},
 
 jQuery.fn.extend({
 	show: function( speed, callback ) {
-		if ( speed != null ) {
+		if ( speed || speed === 0) {
 			return this.animate( genFx("show", 3), speed, callback);
 
 		} else {
@@ -57,7 +57,7 @@ jQuery.fn.extend({
 	},
 
 	hide: function( speed, callback ) {
-		if ( speed != null ) {
+		if ( speed || speed === 0 ) {
 			return this.animate( genFx("hide", 3), speed, callback);
 
 		} else {
diff --git a/src/offset.js b/src/offset.js
index c3183743b..f80574eea 100644
--- a/src/offset.js
+++ b/src/offset.js
@@ -2,16 +2,16 @@ if ( "getBoundingClientRect" in document.documentElement ) {
 	jQuery.fn.offset = function( options ) {
 		var elem = this[0];
 
-		if ( !elem || !elem.ownerDocument ) {
-			return null;
-		}
-
 		if ( options ) { 
 			return this.each(function( i ) {
 				jQuery.offset.setOffset( this, options, i );
 			});
 		}
 
+		if ( !elem || !elem.ownerDocument ) {
+			return null;
+		}
+
 		if ( elem === elem.ownerDocument.body ) {
 			return jQuery.offset.bodyOffset( elem );
 		}
@@ -28,16 +28,16 @@ if ( "getBoundingClientRect" in document.documentElement ) {
 	jQuery.fn.offset = function( options ) {
 		var elem = this[0];
 
-		if ( !elem || !elem.ownerDocument ) {
-			return null;
-		}
-
 		if ( options ) { 
 			return this.each(function( i ) {
 				jQuery.offset.setOffset( this, options, i );
 			});
 		}
 
+		if ( !elem || !elem.ownerDocument ) {
+			return null;
+		}
+
 		if ( elem === elem.ownerDocument.body ) {
 			return jQuery.offset.bodyOffset( elem );
 		}
diff --git a/test/unit/effects.js b/test/unit/effects.js
index cefcc15a4..467631c7b 100644
--- a/test/unit/effects.js
+++ b/test/unit/effects.js
@@ -1,18 +1,36 @@
 module("effects");
 
 test("show()", function() {
-	expect(16);
+	expect(23);
 	var pass = true, div = jQuery("#main div");
 	div.show().each(function(){
 		if ( this.style.display == "none" ) pass = false;
 	});
 	ok( pass, "Show" );
 
-	pass = true;
-	div.hide().show(null).each(function() {
-		if ( this.style.display == "none" ) pass = false;
+	var speeds = {
+	  "null speed": null,
+	  "undefined speed": undefined,
+	  "empty string speed": "",
+	  "false speed": false
+	};
+
+	jQuery.each(speeds, function(name, speed) {
+    pass = true;
+  	div.hide().show(speed).each(function() {
+  		if ( this.style.display == "none" ) pass = false;
+  	});
+  	ok( pass, "Show with " + name);
+  });
+
+
+	jQuery.each(speeds, function(name, speed) {
+    pass = true;
+  	div.hide().show(speed, function() {
+			pass = false;
+		});
+		ok( pass, "Show with " + name + " does not call animate callback" );
 	});
-	ok( pass, "Show will null speed");
 
 	jQuery("#main").append('<div id="show-tests"><div><p><a href="#"></a></p><code></code><pre></pre><span></span></div><table><thead><tr><th></th></tr></thead><tbody><tr><td></td></tr></tbody></table><ul><li></li></ul></div>');
 
diff --git a/test/unit/offset.js b/test/unit/offset.js
index dc03bc2e2..dbaddc862 100644
--- a/test/unit/offset.js
+++ b/test/unit/offset.js
@@ -305,6 +305,13 @@ testoffset("body", function( jQuery ) {
 	equals( jQuery('body').offset().left, 1, "jQuery('#body').offset().left" );
 });
 
+test("Chaining offset(coords) returns jQuery object", function() {
+  expect(2);
+  var coords = { top:  1, left:  1 };
+	equals( jQuery("#absolute-1").offset(coords).selector, "#absolute-1", "offset(coords) returns jQuery object" );
+	equals( jQuery("#non-existent").offset(coords).selector, "#non-existent", "offset(coords) with empty jQuery set returns jQuery object" );
+});
+
 test("offsetParent", function(){
 	expect(11);