EC2 ssh key import failed

Hi,

I am attempting to import an existing SSH key pair from EC2, I select the key from the drop down list, and paste in the private key text. When I click create I am presented with the following error:

Failed to save SSH key : Imported EC2 key data does not look valid

The private key is in the format:

-----BEGIN PRIVATE KEY-----

blahblah

-----END PRIVATE KEY-----

Has anyone experienced anything similar, or is anyone able to help please?

Thanks,

Dan