Blocks in SVCD using TMPGENC

[msilka]

I used TMPGENC to convert an AVI file to MPEG-2.

The video and sound are both converted but I notice that
when the motion on the video is quick blocks appear around the motion and then disappear when it slows down. What settings do I need to tweak to get rid of the blockiness?

I loaded the Super VCD NTSC setting in TMPGENC but there are still blocks.

Thank you