add: else if (ex instanceof jsdIValue) ex = ex.stringValue; 
context: function formatEvalException (ex){    if (ex instanceof BadMojo || ex instanceof Error)        return formatException (ex);        return getMsg (MSN_EVAL_THREW,  String(ex));}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/e014e7e6630afe8d70caa7198725aea7c354a0db/venkman-static.js/buggy/extensions/venkman/resources/content/venkman-static.js