Dutch rabbit sick?

Question
Hello. I wrote to you about the female dutch rabbit that I own that was having sneezing fits. Thank you for your quick and knowlegable response. All is well now with the sneezing but now I have another problem. To re-update you she is about 3-4 months old I believe. She was purchased from a pet store where they kept the rabbits together in a very large area. It was also very clean. She has a very well balanced diet as well. I have owned her for a month.
When she is out of her cage and running around on the bed, floor etc... she is very alert and playful. But since we have had her she shakes her head violenty only when she is out of the cage. She will run around for a bit and be fine, then for a second or two she will shake her head, followed buy a quick jump straight in the air, and then a quick run around the bed. Now I wanted to know if I should be worried about her head shaking. Is she just excited and trying to be playful? Or is it something I should genuinely be concerned about? Thank you for your time.

Answer
That's actually a very good sign - depending on who you talk to it's called a happy dance or a binky.  Rabbits who are very happy will jump up and do 180s and then land and run.

This is a sign of a happy bunny!

So, no, not to worry, it sounds like she likes living with you a whole lot!

Kim