I have had the same bug before today's patch, and I still have it after today's patch.
It happens to me in flight, generaly after triggering a stage. Moments before, the trajectory line was here. After triggering the stage... *poof* ...it's gone.
Hello !
I bought the game in december 2012, and the DLC does not show up in my account on KSP Store...
I really hope you guys will fix the issue. Apparently several early adopters didn't get the DLC.