Interesting article here outling how someone recovered from Panda:
How to Recover From Google's Panda Devaluation
So what was the problem? Apparently Panda considers content that’s great for users to be bad for Google search results. The key here is to do the opposite of what Google tells you to do. Google tells you to think about your customers first. But they’ll penalize you for that. What you need to do is think about what Google wants, because if you don’t please Google’s wacky creatures, your business is toast.
How to Recover From Google's Panda Devaluation