So, every once in a while, I'm drinking a Coke zero. I open the can, nothing happens (that is, it wasn't shaken up and is about to explode or anything).

Anyway, a little bit later it starts fizzing and bubbles come up out of it and it almost overflows as it is continuing to fizz and fizz and fizz.

Then, after about a minute, it stops. The soda is sort of flat after that.

It's happened to me more than once with Coke Zero. WHY DOEES THIS HAPPEN!!??!?!?!

I get that a lot with diet drinks, especially Diet Coke with Splenda. They get really fizzy, especially from the fountain. It must be the lack of sugar.

Let me find it in January and I'll answer you...

all sugar substitutes have this problem.