[C210N]

I like the Homer Simpson version of this:

Something happens to the Simpson's toaster, such that every time a slice of bread goes thru it, they go back in time. Homer happens to swat a prehistoric flea, comes back, and then there is no such thing as doughnuts. So, Homer does toast again, goes back, and whacks something, then returns to find he got his doughnuts back, but something else goes awry... and so on.

[John Locke]

[DManA]

Ah but you forget, after Homer left the "no doughnut" world it started raining doughnuts.