dug 
About finally finding a bug and sending it off to the place from whence non puede salir.
In this case, the animal was a call to Javascript’s .length method, a harmless little tool for extracting the length of a variable (dug = 3 or donkey = 6) such a small thing, but the incorrect value returned was being disguised by a much more complex and much guiltier-looking function that was doing unspeakable things with cookies.
Anyway, two weeks and 437 alert() calls later, I finally found it.
I feel lighter, younger, richer, more beautiful and overall more Zen about this project now :-)