Changing positions when rendering (event crop pan)

Hi, I'm fairly new to the world of editing. I've been working on a project in my spare time for about 9 months, but still pretty bewlidered by a lot of the technical stuff. Having recently learned how to overlay different media on top of each other, I've now hit a problem when rendering. The media is moving around the screen.

Here is the screen in preview (set to Best quality):
http://s1122.photobucket.com/albums/l532/gugliemo/?action=view¤t=phot...
The picture of arnie and the bold text under 'crimewave' are inserted jpegs.

Here is the screen once rendered
http://s1122.photobucket.com/albums/l532/gugliemo/?action=view¤t=phot...
Notice the writing and the picture have moved and the illusion is ruined.

Now the most common problem for this seems to be different specs between video propreties and rendering. I checked and they were indeed wrong:

The Project Video Properties were
720 x 576

The rendering properties were NTSC DV Widescreen (720 x 480)

So I changed the rendering properties to PAL DV Widescreen (720x576)

But the problem remained exactly the same! The rendered avi with matching specs still has the above boxes in the same wrong positions.

Anybody know whats going on?

Hi, I had keyframes turned on for a completely seperate shot, one which I had no problems with the positioning of. But just in case, I turned keyframes off for the entire file, and checked Sync Curser was disabled too. Still have the same problem when rendering.

I went through and rechecked that all the keyframes were off, which they are. However I've noticed a second possible clue:

Although rendering the entire clip causes the boxes to appear in different positions, when I highlight only the problematic clip and select 'preview in player' the problem dissapears. This is the case regardless of whether I select NTSC DV Widesceen OR Pal DV Widescreen.

But whatever setting I choose when rendering the entire project, the problem always occurs.

Another clue: When I change the Project Video Properties to 720x480, the boxes in the preview screen move to where they appear in the full rendering.

So to sum up
- My project video settings are: 720x576
- When I PREVIEW using either 720x576 *or* 720x480, the result concurs with the arrangement on the preview screen (576).
- But when I RENDER the whole project, regardless of whether I do it as NTSC (480) or Pal (576) the result always appear in the wrong place, i.e. appears as 720x480.

All keyframes are deselected, and the fact that the placement of the boxes precisely matches the preview screen *when* the preview settings are altered to 720x480 suggests to me that it is the aspect ratio.

Any idea what's going on??