Vertex Shaders using v1.3 have a tendancy to flip thier matrix points ... its a generic problem with Dx9 because they don't support the Shaders properly.
whilst making a demo for Vertex Shaders in Pro, i gave up on it and put it to the side because it was getting annoying, because when they jump it gets that look what objects get when they share the same coordinates.
Would've made a grand demo

and when i took the shader back into Dx9 it was still dodgy - but when i ran it on a Dx8.2 machine it worked fine.
There are a few more inherint bugs like that which are just because Dx9 is new ... no doubt 9.1 will fixx this but non of the new builds of the beta seem to have.
There was another one with the Projection Mapping, which caused it to distort - some form of data loss i suppose.
If it was with just a single card on just my machines would be annoying but probably something i've done - but i've had a few people test recent tech demos to report the same problems.
It there are a few which could arrise in Pro, but aren't anything to do with it

there's a full list on DirectX.com
Anata aru kowagaru no watashi! 