problems with direct show

[pokazene_maslo]

Hello. I have couple problems with direct show in win7 x64.

1. m2ts playback
problem is in direct show chain. When I render media file in graphedit x64, decoding chain looks like this: haali media splitter ->microsoft DTV-DVD Video Decoder -> ffdshow video decoder -> renderer.
Merit of microsoft DTV-DVD Video Decoder is 0x005fffff which means "normal -1" and this merit can't be changed (don't know why)
ffdshows merit is 0x00800002 which means preferred +2
Question is how to remove microsoft DTV-DVD Video Decoder from the chain permanently? When I remove it manually in graph edit it plays nicely.
x86 chain looks like this: splitter ->microsoft DTV-DVD Video Decoder -> renderer. And again, how to replace microsoft decoder with ffdshow?

2. I have installed avisynth x86 and avisynth x64 but neither doesn't play via direct show. x86 and x64 graphedits just say "cannot render file". How to correct this?

I would really appreciate any help.

EDIT: 1. problem solved with Preferred Filter Tweaker for Windows 7, second problem remains.