Unable to install PDI CE 5.0.1A stable on Mavericks

The instructions say that I should be able to launch the 64 or 32-bit app directly. However, there is only one App. When I try to open it, it says the file is corrupted and should be moved to Trash. Am I missing something? I downloaded the zip a couple of times to make sure it extracted correctly.

Any idea?

Thanks!
Atul