Resolve Lite meltdown

I have installed Resolve Lite (9.1.1) for the 3rd time trying to get it to work but it's not playing ball.

It starts up and I can log in fine. After I have navigated to the folder containing my media (.mov files from my Canon 5D) Resolve doesn't just crash and close, my iMac completely shuts down and restarts. When it starts up again I get the Mac 'your computer encountered a problem and shut down' message.
Like I said I've uninstalled and re-installed to no effect and updated the CUDA software (although isn't that irrelevant seeing as though I have an ATI card?).

Any thoughts?

iMac Late 2009
2.66Ghz i5
12GB
ATI Radeon HD 4850 512 MB
OSX 10.8.2

[Dwaine Maggart]

Per the Mac Resolve Config guide, only 2011 and newer iMacs are supported.

The HD4850 graphics is not adequate for a Resolve GPU.