I know someone who works for an ice-cream company and they run into the same issue. The ice-cream is whipped with air and that air expands as the product moves to higher altitudes causing the containers to overflow and lids to pop off. They only began distributing to the Rocky Mountain region recently after the opening of a new facility at a higher altitude.

Here's an Avatar the Last Airbender/Charlie Brown mashup I did last year:

http://browse.deviantart.com/?qh=&section=&q=Airbender+Charlie+Brown#/d4dx66q

I find Be Quick or Be Dead from Fear of the Dark and The Duellists from Powerslave to be the best Maiden backing tracks for this awesome GIF!