The resource map is a template that interprets the resource forks in any
file into something intelligent. The Macintosh OS generates ID bombs
(between -192 and -199) if it finds a serious problem in the resource fork.
We suspect that the message was generated by another application or
utility. If it happened only once, don't be alarmed. However, we suggest
running a file verification utility against the hard drive and possibly
backing it up (just in case).