Cannot open file because identity of developer cannot be verified

Hi,

I cannot open a Text-Animation file I downloaded from: http://www.blender.org/download/

The msg. I get from Core Services says: "Blender can´t be opened because the identity of developer cannot be verified"

It does´nt matter if I double or Richt-Click to Open.

Is there a way to get the developer verified???

(Would really like to use this App!).

Thanks in advance for any suggestions!