DNxHD36 Data Rate High

I am currently trying to use Compressor 4.2.1 to export some DNxHD files. I have the latest and greatest Avid Codecs 2.6 The issue is when I export using DNxHD 36 setting, compressor is not keeping the data rate to 36mbps, it is allowing it to go up to 175mbps. Instead of expected file sizes to be around 3-4GB, I am getting 25-30GB video files. When I try and use MPEGStreamclip to accomplish the same task, it is giving me video files that are capped @ 36mbps. With the 6 minute 42 second test file I am using, the MPEGStreamclip output is a 1.82GB files, while Compressor's version is 8.85GB

This sounds like a bug to me, is anyone else having similar issues?