Same problem here, When exporting using the same settings as CS3 to Quicktime using H264 Codec i am getting a very pixelated output. I think it may be the bitrate, but whenever i change it i go back in to export and its set as 1000 by default, its like a am making the changes and the media encoder doesn’t pick them up. i have tried saving it as a preset but again when i go back in the bitrate is set to 1000 even tho it was saved higher in the preset.