Hi and thanks for getting involved - here is the link to the offending film http://www.youtube.com/watch?v=K6n0JHG8ld0. Pretty much the whole movie is affected and i think the pan/zzom was a red herring...

On advice from Adobe, I cleaned the cache and renewed the "5.5" folder in the data cab and the wobble/bounce has diminished from 5beats/sec to 2beats/sec (dont ask me why!)

It's less perceptible but its still there...

Since posting ive also discovered other threads about this and it seems to be a problem for others. And a stubborn one too.  Attention in other threads seems to be focussed on the match of the original material with the settings of the sequence.  Since the original material in my case was a ragbag of stills in different formats and bit depths this could be the prob.  Furthermore ive found the tolerance of CS5.5 to be extremely forgiving on mixing content with different frame rates on different original materials with no wobble ensuing...this issue is a stills-to-video issue it seems to me.

Interesting idea; but the positions change as the image moves so do you mean the start and end points of the keyframes in the "Position" effects module?

all settings to factors of 8 and still wobbling

I had secretly hoped this would fox it

but no

any more suggestions?

scratch that  - I found it. Need to do on all slides...on it

Issue Resolved!

90 minutes with Adobe support (Paul Ashish; you're a God) and we cracked it.  Here are the lessons for all to share and take note:

1. My system had a wonky copy of quicktime so we refreshed the version that helped. 

2. I was not opening the prog "as administrator" which I now will in all cases - u will not be able to do this unless you have a fresh quicktime anyway.

3. There is a magic bullet button on the export settings page called "Match settings" clicking this did a number of things given the nature of my original material which included a wide variety of source files all without attendant support info folders which the memory stick on the camera they were taken would have made available (they arrived with me via dropbox).

4. Choosing the Youtube HD preset as an export setting in h264 seemed like a good idea but it sent the file to a DIVX format which didnt help either.  Clicking Match settings on export meant PP could "assume" some of the missing settings since the original support files and folders associated with the material werent there AND it sent the output to a Media Player format (mpeg) which showed no bounce.

5. While DVIX is a not too bad player Downloading VLC player helped too.

Watch it bounce-free at http://youtu.be/w2WuVyVBn6o

I am one happy boy and cant recommend Adobe Support enough.

Over and out.