Disabling screensaver doesn't work but I have come up with an alternative I hope.
the command
defaults -currentHost write com.apple.screensaver idleTime -int 28800
I'm hoping will set the screensaver to come on after 8 hours, haven't had 8 hours to test it yet or test what maximum integer can be inserted, or if this needs to be re-applied at startup.
Anyone with any thoughts?

This seems to work fine I have now entered 16 hours 16x60x60=57600
I can live with my screensaver coming on after sixteen hours lol
you can check the value after reboot by
defaults -currentHost read com.apple.screensaver idleTime -int

Hehe, nice workaround. :)

However, why doesn't it work? It works fine here! Any Errors in the System Log regarding this issue?

Nope none, I can adjust time with slider, but disable doesn't work and if I use a hot corner to disable that doesn't work either, seems i'm not alone in that some real macs suffer from this too.

I have the same problem with random crashes, sometimes involving the screensaver even though I have it set to never it still comes on!, I however am not willing to turn off my onboard lan as I need them for both OS I use hopefully there will be some new nvid. network drivers in the new revision that will fix this problem, Im also hopping we see a new kernal that allows sleep in some form or another as sleep is not supported in this revision.

I will also try your method as It seems to crash after 8 hours or so and its always after the screensaver.

Good Luck