Cannot open hpl2editorsuite.dmg

[Dobzilla]

I've just installed Amnesia: The Dark Descent on Steam, everything works fine. But I tried installing the editor suite and I ran into a problem. When I try to open up the .dmg file it comes up with an error message saying
"The following disk images couldn't be opened - hpl2editorsuite.dmg - reason, not recognised. This also happens when I try to open up the manual file too.

The system I'm running is - Mac OS X version 10.6.8

Help would be much appreciated

[jens]

Sound like the download might not have finished successfully, try downloading again.

[Dobzilla]

Sound like the download might not have finished successfully, try downloading again.

I've re-downloaded both files a few times but I still get the same problem :|