The moisture in the gas does happen. Jody at weldingtipsandtricks did a DIY filter for that a bit ago (or $8 at HF you can get a smaller filter like Jody's).
http://www.everlastgenerators.com/fo...t=argon+filter
It has been a rare problem, but seems like more and more these days. Mark called it first years ago and sure enough we see it on and off. I know Ray has had them as well.
I've had people in Tx and Ca with the problem. Not sure if only AirGas but I know some where.