Does GB-PVR capture DVD Compliant MPEG2's??

[sylv]

I use the following settings for my recordings:
. NTSC 720x480
. variable bit rate
. bit rate: 3500 kbps
. bit rate peak: 7200 kbps
. autio bit rate: 224
. audio sample rate: 48 khz

which, based on previous posts seems to be dvd-compliant mpeg2. However, when I author dvd with Ulead Movie Factorie 3 SE, it takes forever (around 45 min for 1h30 of play time) and it introduces artefacts in the video. It looks like it reencodes the video. The dvd video is of lower quality than what I get when looking directly at the original mpeg file via the MVP. In Ulead options, I specifically select to not convert mpeg compliant files.

Does anyone would know what might be going wrong?

Thanks!