subtitles resynchronization problem

Hey, I've come across the following problem: When I set the subtitles to a film and they have bad timing I need to resynchronizate them via tools->track synchronization However, when I need to advance the subtitles over the video for x seconds (let's say x=20), then I really play the movie for those x seconds so that they finally work as intended...And when I have to resynchronize the subtitles 3 times during the movie, it's a real bummer... Can you guys somehow fix it, please? So that the subtitles would work immediately after I resynchronize them by x seconds? Not after another x seconds?

Thank you!

PS: eventually (I know it's hard - it's just an idea - if you don't like it just ignore it) you could make an interface like this: when the subtitles have bad timing in a specific sentence ("This is just the sentence that just has been said") you enter this interface and type this sentence(or a part of it) in it so that it would search for the sentence and auto synchronize)...