Yeah, that is the same process I do as well. Worth a shot, let us know if it happens to fix your issue. I think I've tried it 4 times now, as soon as I had the issue, I pulled the bag out further, and it completely stopped.
I wanted to post my experience with the cavitation, as it may help someone else with similar issues. My issue was extremely simple - it was 100% related to the bag. If I pull the bag over the kettle edges as far as it will go, I have no issues. If I just go over the edges a couple of inches...
There is also the KC Bier Meisters, meetings are the 3rd Friday of the month. Large group with about 100 members in total, and about 33% are certified judges. Www.kcbiermeisters.org
Thanks Jhobson! Another bad question, which of these would i want?
http://www.auberins.com/index.php?main_page=product_info&cPath=7_32&products_id=303
http://www.auberins.com/index.php?main_page=product_info&cPath=7_32&products_id=223
http://brooklynbrewshop.com/ does 1 gallon kits within a 1g jug. They recommend a blow off tube during the active part of fermentation, and then switch to an airlock later.