Hi
If you are prepared to lose a fair bit of your image at the top and bottom you can "create" an oval transition. It won't be perfect but worth having a try..
Proceed as follows....You will have to experiment with this procedure. 
Place the APPEARING clip (that's the one showing the transition) onto the timeline. (Clip 2)
Place the clip that comes before it in front of this. (Clip 1)
Select Clip 2 and add the SCALE effect.
Increase the Y% value to produce a heighting effect opposite to the degree of flattening you want in the round transition. You will have to experiment here. Use the same Y% value on both clips. Note that the more you heighten the clips the more of both clips will be lost at the top and bottom in the finished output.
Now add your circle transition to Clip 1 in the normal way.
Save (Export) the sequence to your PC.
Reload the saved sequence and select it.
Add the "Scale" effect once more but this time reduce the Y% value to restore the sequence (It will be one clip now) to its original proportions...or at least as close as you can get.
This step will reduce the height of the clip producing the chequered areas at top and bottom.
Place the timeline cursor at the centre of the transition so you can see the preview.
To get back to full screen now apply the CROP effect choosing your desired aspect ratio e.g. 16:9
Reduce the sides of the orange rectangle until there is no chequered arrea showing.
The sequence should now play (enlarged of course) with a horizontal oval transition.
It's about the best you will be able to do with VP in the absence of a proper oval transition.
You could also create a black oval vignette in a similar way using blank frames, one black and one green and then after going through the steps, adding the result to an overlay track with the chroma effect set to render the green transparent.
Nat
