FaceTime loading

I want to load faceTime on my brothers I-Mac but it every time I try I get the message to load Security Update 2010-005. This I have done but still can not load FaceTime as it stills says load the update

What version of the OS are you running ?

Cheers ... McBie

Snow Leopard -

Exact version number please... 10.6.what?

Sorry - it is 10.5.8

Face Time will not work in 10.5 of any flavor.

Thanks for that - I had not realised my brother had not updated to 10.6.8 - he lives a fair distance from me - hence trying to set up face time.