SharePoint 2010 ribbon stuck at Loading

Hi All

I am using window 7 operating system,SharePoint 2010

In local system SharePoint site ribbon displaying as 'Loading' only, when i click on library tools.

am i missing anything in Master page ?

I checked with other sites, every thing is fine.

and also i changed masterpage from custom masterpage to V4, this time library tool displaying there is no loading message.

Thanks & Regards

MD.Liakath ali