hi,
i found a serious bug in any cam-solve i did...

- i solved a clip (with distortion values set in ClipEditor - in this case K1 and K2 are set to -0.1 and 0.05)
- i click "set backound" and "setup tracking scene" buttons
- goto 3d-view
- now the clip in 3d-view background is not shown undistorted
- check/uncheck the "Render Undistorted" checkbox - nothing changes

it should be shown undistorted - because the checkbox "Render Undistorted" is checked

my first thougt was - okay i have to build a undistorted proxy for my clip (in the clipeditors proxy panel)
so i do
- goto clipeditor
- build proxy for the clip (build undistorted)

i realized the error because i did following
- go back to 3d-view
- change backgound-img to show "proxy undistorted"

now its shows the undistorted proxy like it should
NOW THE ERROR :)
now you can switch the BG-image-clip back to "NO PROXY / FULL RENDER"

and now - magicaly - the checkbox "Render Undistorted" works on the original footage

even if i deleted the proxy files this work now

CONCLUSION
i have to build clip-proxy to get the checkbox "Render Undistorted" in 3D-View´s Background-Image to work

must be an initialization-error in 3d-bg-image for movie clips
maybe it gets no distortion-value from movie-clip or its gets not applyed

sorry for the long text - english is not my language ;) and that thing confused me a looooot :)
byebye
Tobi