Why is my frame rate so bad in Final Cut?

When I import an HD video from my Nikon D7000 and play it back, the frame rate is so terrible.Am I doing something wrong?

Please note that I'm a beginner and I'm still learning. Thanks in advance!

Added (1). Note: It happens after I drag the media file into the sequence, a box comes up that says:

Attention - This clip does not match this sequence's settings or any of your sequences presets.

For best performance your sequence and External Video should be set to the format of the clips you are editing

Change the sequence settings to match the clip settings?

Then the options are Yes and No. Does this have to do with anything? What should I click to stop it from dropping frames?

Mmm, I don't think your doing anything wrong. I think that your computer is just having a hard time processing data from that amazing camera of yours. Maybe you could upgrade your ram?