I have a Dimension P4 2.5G and 1G memory.  I have an internal DVD writer (x4)

I use Ulead DVD Movie Factory 2 SE to create DVD discs. 

I have this problem and I need your help: voice and video do not syncronize perfectly in my finished DVDs.  The difference is about 2 seconds.  It starts well and perfectly syncronizes, but at the end of the movie (2 hours), the voice is 2 seconds or so faster than the video. 

I called Ulead, but they have no solution.  I tried to correct this problem using different bid rate and so on, but the problem is still the same. 

Does anybody have any solution to this problem?

Thanks,