The problem is most likely what you are doing in AE. If you are adding sharp titles for example. The DV codec does not like sharp lines. No quality is lost in Premiere Pro. The quality is lost going to the DV codec. Even Avid would have the same problem.
Please expand on what you are doing in AE so we might be able to assist you better. You are taking captured video and doing what to it?
Steven
Adobe Premiere Pro 1.5.1 / After Effects 6.5 Pro https://www.stevengotz.com
Learning Adobe Premiere Pro 1.5 https://www.lynda.com
Contributing Writer, PeachPit Press, Visual QuickPro Guide, Premiere Pro 1.5