Comment # 39 on bug 1179296 from Stefan Dirsch

I just had a deeper look into this. And I noticed there are no quirks in
Xserver to remove Interlaced modes from EDID. I'm afraid this is nothing I can
fix. Also you may have replaced your monitor meanwhile. At least you're living
with this workaround for 2 years now. Let's face reality and close this as
WONTFIX. I'm sorry!