Braces around most fields is overzealous. Many fields do not require double braces at all, in particular fields with integer numbers.
Inspired by this thread which describes a very similar problem: http://tex.stackexchange.com/questions/10587/latex-error-when-citing-paper-with-similar-authors-and-same-year-using-natbib , I created a small patch (attached) to only protect titles when the "protect capitalization" option is used. I expect this patch will solve the bug described.
Braces around most fields is overzealous. Many fields do not require double braces at all, in particular fields with integer numbers.
Inspired by this thread which describes a very similar problem: http:// tex.stackexchan ge.com/ questions/ 10587/latex- error-when- citing- paper-with- similar- authors- and-same- year-using- natbib , I created a small patch (attached) to only protect titles when the "protect capitalization" option is used. I expect this patch will solve the bug described.