i've noticed some complaints about naruto and other stuff having very little play time... i have had the same problem and have found the cause of it, which is pretty disappointing. Dattebayo's and some other subber's videos have bad header's. Basically what that means is the audio time and video time are not completely in sync.
HERE'S THE BAD NEWS : THE ONLY FIX FOR THIS IS RE-ENCODING THE VIDEO.
Oh, and if you want to know how i figured this out i compared the broken avi files with ones that had the full time shown using abcAVI tag editor.