dahmum = D = dangling pointer

dancing frog n.

[Vancouver area] A problem that occurs on a computer that will not reappear while anyone else is watching. From the classic Warner Brothers cartoon "One Froggy Evening", featuring a dancing and singing Michigan J. Frog that just croaks when anyone else is around (now the WB network mascot).

--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.