May be, I found a bug. Look at the screenshots I made. Source ist totally fine. Indexing with DGAVCIndex brings big block artefacts.
Uploaded 1 min of the source stream. I use Alpha 6 with Original libavcodec.dll. Didn't try tryout.dll, just recognized it yet.
http://rapidshare.com/files/43901389/dga.h264.html
Source has 720p.