No, I don't think you're doing anything wrong. If you've made some major site changes and recently and the "similar" link was showing before and now it's not then you might take a look in that direction.
I would also take a look at Google Webmaster Tools just to make sure that there are no errors or anything you might need to address.
Thanks bhartzer. We have done the redirection of the home from our sub-domain URL (Dynamic) to a static URL under main domain.
We redirected the URL from
We have lot of static pages under the main domain. Once the user login, we will take him to the subdomain. Previously all the pages are under the sub-domain. This is the major change we did. We would have done some mistake in this redirection.