I have a strange problem. Im mixing Direct3d 10 and Direct2d using SlimDX. When I try to draw to the Direct3d backbuffer using Direct2d, I get artifacts when using the FillEllipse() and DrawEllipse() methods. It looks like the triangulation of the primitives is messed up or something like that. Other methods like FillRectangle() is fine. Ive attached a screenshot showing the result.
When drawing Direct2d to a texture and then draw that texture to the backbuffer using regular Direct3d stuff works fine.
The Direct3d10 device is created with Bgra support
Direct2d part of the renderloop looks like this; (snippet)