To scroll frame by frame, you have to pause the movie, then use arrow keys.
Remember you can't go before the start seeking point.
If you can't seek forward, maybe try to:
1. Play the movie 'till the scene you want to seek frame by frame
2. Pause the playback
3. Press the RIGHT key once (or twice, you have to see the image go forward by only ONE frame)
4. Press the LEFT key until you reach the starting poin (where you pressed the PAUSE button)
5. Now try to seek forward (the seeking problem should be gone)
I posted this problem somewhere in the forum, but I don't remember where
