I use Sony Vegas Platinum 9 and I had never problems with this program.
I use it very often for 3d animation final cut. I used to import frames to make the animation sequence ready, but now something is strange. I drag for example 200 frames to the timeline and the result is 2 frames and space, 2 frames and space etc. I have 1 frame at 29,970 fps in Preferences like before, but it doesn`t work now. I tried Trial Vegas Pro and it works with the same settings