Ulead audio sync problem

I captured continuously two one-half hour shows (for a total of 1 hr) with WinTV PVR 250 capture card with Standard DVD play setting. I did this on 3 separate occasions. Then I brought the three one-hour recordings, one-by-one, into the Ulead Moviefactory and burned on three separate DVDs. When I played them back, the first half-hour goes without a glitch. But, the second half-hour recording, in all 3 DVDs, has the “mouthing” trail the audio by about 20 secs. This happened in all three DVDs. The result is baffling because the two half-hour shows were captured continuously (no break at all). Given the regularity of the problem, can anyone advise me as to what I should do. Many thanks._X_X_X_X_X_[small]gkrshnn[/small]