Cruzer Blade- problem installing vault on mac

 I have just bought a 64GB Cruzer Blade but have a problem installing the Vault on my Mac OS X 10.6.8. But it does work fine on my other Windows computer.
  I have followed the instructions that came as a file on the USB and downloaded the latest SanDiskSecureAccessV3_mac. But when i click on the folder i get the following message
“sandisk secureaccess v3 mac cannot be opened because of a problem”  ???