Only thing I have to say is if the coop guys say they don't know what went wrong they are not telling the truth or are stupid.

We seed 1000's of acres a year with air flows and have no problems.

You need to KNOW your machine and KNOW how to run it.  We only double spread it it is less than 15 acres or so.  

I am driveing by some grass I seeded a month ago and will get some pics tonight.