T-U and Oshyan, great advice. I found some other threads in the forums dealing with foliage flicker and the higher AA settings were mentioned as a possible solution. Sometimes I forget that the sliders can be set outside of the 'recommended' range
. I bumped the AA up to 11 (with the customized sampling) and rendered without deferred atmosphere. That took care of a lot of the problem. It was still there, but greatly reduced. I'm now re-rendering at AA 12 and that should do it.
T-U, I felt exactly the same way about the camera motion so I ended up redoing it. It still moves quickly, but it spends more time ramping up in speed and hangs out in the trees longer (I just love the way the tree trunks and grass look). I was considering rendering out the different layers as well, I just have to budget to see if my hard drive has enough space..........
Thanks again for the advice (and letting me hijack yesmine's thread). Terragen's rendering engine is awesome, but it definitely requires a different way of thinking compared to the path tracers I'm used to.