I have changed the theme of my website but Plugings are Not Working Like Inline Ads Plugin & Stats Plugins etc...
Have you tried reinstalling them?
Reactivating should fixe the issue, or manually add the variables into your new templates.
I believe that this is meant with the above 'reinstalling': remove the plugin file from your server, but
first deactivate it of course, and then upload and activate it again.
In the postbit template it should have {$post[inline_ads]} instead of {$seperator} at the very bottom.