Do you happen to know which Mpeg codec you're using?
I know this bug was reported earlier, but it seemed to also depend on the version of the Mpeg codec used. So maybe upgrading to a newer Mpeg codec could perhaps do the trick?
Further, if you just wish to move on to certain times in the movie to capture some screens, can't you (instead of "jump to") pause, then draw the "progress slider" to the right to the (approximate) point in the movie, and then unpause to resume playing till you reach the point where you wish to capture the screen.
If that works you need not have so much patience and waste time to see the whole movie to reach those points.
