Thanks for the reply, here are my answers to your questions: I was viewing on a CRT all down the line. The entire project was in PAL, every step. I had to output onto a hard disk because I didn't have the tape machine the client wanted to project to mastered on (DV). So in order to get it out onto tape, the only possibility was to load from the hard disk onto the AVID and then out again. As soon as we looked at the material over the AVID, we could see the problems with jerky pictures.
But later on, I had the chance to go from the hard disk onto a Final Cut system and then out to tape. I didn't see the problems when playing directly from Final Cut or even after recording to tape and looking at it in the Final Cut editing suite on a CRT. We only saw problems when we took it into the control room to be broadcast. They also had a DV machine to play back on and we looked at the material over a broadcast monitor.
Are there really problems with compatability of different NLE systems? I didn't know that. But still, that alone would not explain my problems. Would be grateful if you have any thoughts on this - or if anyone does!