If you are using a DV sequence, then you are compressing your pictures 5:1. DV is known to be bad for pictures, titles and graphics.
If you work in an 8-bit uncompressed timeline, things will look MUCH better.
TV resolution is 720×486…so that is the best your timeline can get. Unless you go HD and get either 1280×720 or 1920×1280…but then you would lose that as you go to DVD as there are no HD DVDs yet that play back on consumer equipment.
Shane Ross
Alokut Productions
http://www.lfhd.net