diff --git a/AppKit/CPTabView.j b/AppKit/CPTabView.j
index 7a9f86697..31c6d1c51 100644
--- a/AppKit/CPTabView.j
+++ b/AppKit/CPTabView.j
@@ -48,7 +48,7 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
     CPNumber            selectedIndex;
 
     CPTabViewType       type;
-    
+
     id                  delegate;
     unsigned            delegateSelectors;
 }
@@ -59,20 +59,23 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
     if (self)
     {
         items = [CPArray array];
-    
+
         tabs = [[CPSegmentedControl alloc] initWithFrame:CGRectMake(0, 0, 0, HEIGHT_OF_SEGMENTED_CONTROL)];
         [tabs setHitTests:NO];
-    
+
         box = [[CPBox alloc] initWithFrame:CGRectMake(0, HEIGHT_OF_SEGMENTED_CONTROL / 2, CGRectGetWidth(aFrame),
                                                             CGRectGetHeight(aFrame) - HEIGHT_OF_SEGMENTED_CONTROL)];
-    
+
         selectedIndex = CPNotFound;
-    
+
         [self setTabViewType:CPTopTabsBezelBorder];
         [self setBackgroundColor:[CPColor colorWithCalibratedWhite:0.95 alpha:1.0]];
-    
+
         [self addSubview:box];
         [self addSubview:tabs];
+
+        [box setAutoresizingMask:CPViewWidthSizable];
+        [tabs setAutoresizingMask:CPViewMinXMargin | CPViewMaxXMargin];
     }
     return self;
 }
@@ -96,7 +99,7 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 - (void)insertTabViewItem:(CPTabViewItem)aTabViewItem atIndex:(unsigned)anIndex
 {
     [items insertObject:aTabViewItem atIndex:anIndex];
-    
+
     [self _updateItems];
     [self _repositionTabs];
 
@@ -120,7 +123,7 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 
     [self _updateItems];
     [self _repositionTabs];
-    
+
     if (delegateSelectors & CPTabViewDidChangeNumberOfTabViewItemsSelector)
         [delegate tabViewDidChangeNumberOfTabViewItems:self];
 }
@@ -181,7 +184,7 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 {
     if ([items count] === 0)
         return; // throw?
-    
+
     [self selectTabViewItemAtIndex:0];
 }
 
@@ -193,7 +196,7 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 {
     if ([items count] === 0)
         return; // throw?
-    
+
     [self selectTabViewItemAtIndex:[items count] - 1];
 }
 
@@ -205,12 +208,13 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 {
     if (selectedIndex === CPNotFound)
         return;
-    
+
     var nextIndex = selectedIndex + 1;
-    
+
     if (nextIndex === [items count])
-        return; // does nothing. According to spec at (http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Reference/ApplicationKit/Classes/NSTabView_Class/Reference/Reference.html#//apple_ref/occ/instm/NSTabView/selectNextTabViewItem:)
-    
+        // does nothing. According to spec at (http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Reference/ApplicationKit/Classes/NSTabView_Class/Reference/Reference.html#//apple_ref/occ/instm/NSTabView/selectNextTabViewItem:)
+        return;
+
     [self selectTabViewItemAtIndex:nextIndex];
 }
 
@@ -222,12 +226,12 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 {
     if (selectedIndex === CPNotFound)
         return;
-    
+
     var previousIndex = selectedIndex - 1;
 
     if (previousIndex < 0)
         return; // does nothing. See above.
-    
+
     [self selectTabViewItemAtIndex:previousIndex];
 }
 
@@ -250,16 +254,18 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 
     if (anIndex === selectedIndex)
         return;
-    
+
+    var aTabViewItem = [self tabViewItemAtIndex:anIndex];
+
     if ((delegateSelectors & CPTabViewShouldSelectTabViewItemSelector) && ![delegate tabView:self shouldSelectTabViewItem:aTabViewItem])
         return;
 
     if (delegateSelectors & CPTabViewWillSelectTabViewItemSelector)
         [delegate tabView:self willSelectTabViewItem:aTabViewItem];
-    
+
     [tabs selectSegmentWithTag:anIndex];
     [self _setSelectedIndex:anIndex];
-    
+
     if (delegateSelectors & CPTabViewDidSelectTabViewItemSelector)
         [delegate tabView:self didSelectTabViewItem:aTabViewItem];
 }
@@ -281,18 +287,19 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 {
     if (type === aTabViewType)
         return;
-    
+
     if ((type === CPTopTabsBezelBorder || type === CPBottomTabsBezelBorder)
             && (aTabViewType !== CPTopTabsBezelBorder && aTabViewType !== CPBottomTabsBezelBorder))
         [tabs removeFromSuperview];
-    
+
     if ((type === CPNoTabsBezelBorder || type === CPNoTabsLineBorder || type === CPNoTabsNoBorder)
             && (aTabViewType !== CPNoTabsBezelBorder && aTabViewType !== CPNoTabsBezelBorder && aTabViewType !== CPNoTabsNoBorder))
         [self addSubview:tabs];
-    
+
     type = aTabViewType;
-    
-    switch (type) {
+
+    switch (type)
+    {
         case CPTopTabsBezelBorder:
         case CPBottomTabsBezelBorder:
         case CPNoTabsBezelBorder:
@@ -357,7 +364,7 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 - (void)mouseDown:(CPEvent)anEvent
 {
     var segmentIndex = [tabs testSegment:[tabs convertPoint:[anEvent locationInWindow] fromView:nil]];
-    
+
     if (segmentIndex != CPNotFound)
     {
         [self selectTabViewItemAtIndex:segmentIndex];
@@ -369,7 +376,7 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 {
     var horizontalCenterOfSelf = CGRectGetWidth([self bounds]) / 2,
         verticalCenterOfTabs = CGRectGetHeight([tabs bounds]) / 2;
-    
+
     if (type === CPBottomTabsBezelBorder)
         [tabs setCenter:CGPointMake(horizontalCenterOfSelf, CGRectGetHeight([self bounds]) - verticalCenterOfTabs)];
     else
@@ -379,7 +386,7 @@ var HEIGHT_OF_SEGMENTED_CONTROL = 24;
 - (void)_setSelectedIndex:(CPNumber)index
 {
     selectedIndex = index;
-    
+
     [box setContentView:[[items objectAtIndex:selectedIndex] view]];
 }
 
@@ -432,7 +439,7 @@ var CPTabViewItemsKey               = "CPTabViewItemsKey",
 - (void)encodeWithCoder:(CPCoder)aCoder
 {
     [super encodeWithCoder:aCoder];
-    
+
     [aCoder encodeObject:items forKey:CPTabViewItemsKey];;
     [aCoder encodeObject:[self selectedTabViewItem] forKey:CPTabViewSelectedItemKey];
 
diff --git a/Tests/AppKit/CPTabViewTest.j b/Tests/AppKit/CPTabViewTest.j
new file mode 100644
index 000000000..9bba62b40
--- /dev/null
+++ b/Tests/AppKit/CPTabViewTest.j
@@ -0,0 +1,65 @@
+@import <Foundation/Foundation.j>
+@import <AppKit/AppKit.j>
+
+
+
+@implementation CPTabView (TEST)
+
+- (CPSegmentedControl)tabs
+{
+    return tabs;
+}
+
+@end
+
+
+@implementation CPTabViewTest : OJTestCase
+{
+    CPTabView       _tableView;
+    CPTabViewItem   _tabItem1;
+    CPTabViewItem   _tabItem2;
+}
+
+- (void)setUp
+{
+    _tabView = [[CPTabView alloc] initWithFrame:CGRectMake(0, 0, 800, 600)];
+    
+    _tabItem1 = [[CPTabViewItem alloc] initWithIdentifier:@"id1"];    
+    [_tabItem1 setLabel:@"Item A"];
+    [_tabItem1 setView:[[CPView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)]]
+
+    _tabItem2 = [[CPTabViewItem alloc] initWithIdentifier:@"id2"];
+    [_tabItem2 setLabel:@"Item B"];
+    [_tabItem2 setView:[[CPView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)]]
+    
+    [_tabView addTabViewItem:_tabItem1];
+    [_tabView addTabViewItem:_tabItem2];
+}
+
+- (void)testCreate
+{
+    [self assertNotNull:_tabView];
+    
+}
+
+- (void)testMiddle
+{
+    var tabs = [_tabView tabs];
+    [self assert:([_tabView frameSize].width / 2)  equals:CPRectGetMidX([tabs frame])];
+}
+
+- (void)testMiddleAfterMoveFrame
+{
+    var tabs = [_tabView tabs];
+    [_tabView setFrame:CPRectMake(10, 100, 1000, 200)];
+    [self assert:([_tabView frameSize].width / 2)  equals:CPRectGetMidX([tabs frame])];
+}
+
+- (void)testMiddleAfterMoveBound
+{
+    var tabs = [_tabView tabs];
+    [_tabView setBounds:CPRectMake(100, 100, 20, 300)];
+    [self assert:([tabs boundsSize].width / 2)  equals:CPRectGetMidX([tabs bounds])];
+}
+
+@end
\ No newline at end of file