Actually using Vegas Movie Studio (consumer/lower cost version)
I like it because it supports Many codecs, and doesn't limit the shape of the media (any non standard dimensions, eg 10px tall x 1280px wide)
Its seems all encoders that use QT engine for encoding fail to provide Directshow AVI codecs (eg: Batch from Livid)
Other rather powerful encoders like MediaCoder x64 and MPEG_Streamclip also don't seem to offer this Hap avi codec.
I have had success with Virtual Dub. http://virtualdub.org/
It requires additional plugins to be installed if you want to open Quicktime video files, but supports most Windows formats by default.
This will likely be the Free option that I recommend.