Sadly you can't assume that just because something was safe the first time you checked it that it still is. I did the shopping without the boys last week. Since I had the time I decided to double check all the 'safe' brands that I usually buy.
It turns out that Bulla has changed the ingredients in its vanilla ice-cream. Luckily I discovered the Weis ice-cream so now I'm in ice-cream heaven.
So, the moral of my little tale is please re-check every now and then because companies won't tell you when they pop a nasty new additive in.