New 20" iMac and Second Life?

I've been playing off and on over the last week and a half, and can;t say I noticed more than that dip in brightness I've seen reported recently.

Until today... I upgraded my RAM again, now up to 3GB and while running SL, I got a kind of milky blue cast to all the white on the screen... what's more the dips in brightness are very real.

I am out of ideas here...


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When I say all the white, I mean the white in the menu bar, in Safari, in the finder windows... everything... quitting Second Life did not help, I had to restart.

Howdy, what kind of flickering are we talking about here?

I've just been running SL (first time in ages) on my newish 20" iMac (aluminium, not the cheapest model but next one up) and all the textures keep flashing. It's rather annoying. The top of the iMac does get very hot...