Apparently, the inner lining separates and creates big problems. Pics, not mine though.

I guess the older lines were never made to handle today's high levels of ethanol. I haven't read anything about other brands yet. Apparently, the new Mercury lines are gray with blue writing on it and supposely safe from the use of ethanol, at least for a couple of years. They were just recently released too.
Bah, now I have to spend more money, just when I thought I was done.