Every once in a while - it's hard to know under what circumstances, exactly - messages of the form:
2007-08-04 05:20:28.877 dx86cl64[3870:613] Exception raised during background layout: -[NSLayoutManager _fillLayoutHoleForCharacterRange:desiredNumberOfLines:isSoft:] *** attempted layout while textStorage is editing. It is not valid to cause the layoutManager to do layout while the textStorage is editing (ie the textStorage has been sent a beginEditing message without a matching endEditing.)
2007-08-04 05:20:28.880 dx86cl64[3870:613] -[NSLayoutManager _fillLayoutHoleForCharacterRange:desiredNumberOfLines:isSoft:] *** attempted layout while textStorage is editing. It is not valid to cause the layoutManager to do layout while the textStorage is editing (ie the textStorage has been sent a beginEditing message without a matching endEditing.)
get logged.
There's usually a good deal of effort involved in ensuring that layout (redisplay) is inhibited while editing (modification of the buffer) is in progress.
It's possible that this has something to do with the mechanism that tries to ensure that a paren - which might have been blinking - is drawn properly.
