Bad gas usually has to do with water, or gas that has been sitting for a while. The unleaded gas doesnt have the shelf life of the old leaded stuff. Additives really wont help with old gas, but you can usually smell it.
I run non ethanol 92 get it one of the same 2 places everytime and not had a problem. This last trip water alarm went off. I also run startron. It can happen, although I am wondering if perhaps the water sensor is bad.