Your definition is correct. The term heisenbug has been around for quite a while, for example, it's in the Jargon File: http://catb.org/jargon/html/H/heis

Your definition is correct. The term heisenbug has been around for quite a while, for example, it's in the Jargon File: http://catb.org/jargon/html/H/heisenbug.html I have no idea where this guy got his nonstandard usage of the term from.