tk2dSprites render behind other meshes with 2 cameras

[zblack]

I have one camera that renders all 3D stuff set to a depth of 1. The UI camera renders tk2d sprites with a depth of 2. In Perspective mode (3D camera), the order is obeyed. But if I change the 3D camera to orthographic, the tk2d sprites are occluded. I have tried setting Camera.transparencySortMode but the issue isn't fixed.