I'm wondering if the preview quality in the project window of Premiere is supposed to be just a rough quide - or visually accurate of the cineform quality.

I find that the image is softer than the source video and movement ghosts. I don't have this problem if I play the same AVI in Windows Media Player for example. Is this normal? I've tried all the cineform settings for preview quality, and different project sizes 1440, 1920 etc, improved things a bit, but all the same issues remain. I've also tried the newest trial versions of Cineform offerings.

My PC spec is not a problem. I have a geforce 9800 if that makes a difference?

Disable Preview playback is the only mode that controls this. If you playing interlace content you will have more issues when using a progressive display, as we don't force deinterlacing on the output (WMP does typically) as it is import to see all your field data.

also, why does the colour shift when you hit playback. I've disabled YUV playback option etc , but the video still gets brighter when played.

I thought I had a solution to lack of BlackMagic timeline preview, in that I used the BM timeline to calibrate my Premiere window with the HDMI output on my 10bit LCD Bravia. In that setup they both look identical. I assumed then that cineform project window would be matching my destination, which it doesn'tbecause of this brightness shift (when it's not playing it does match).

I'm not up on colour space management, just going by what I see.

Deniz, that is not related to this post. Color shifts are NVidia calibration issues, described on this form many times.