2.0.7，捕抓的js错误经常有 cocos2d-jsb.js的，问下是什么情况才会出现？
TypeError: null is not an object (evaluating "this._callbackTable[t]")
src/cocos2d-jsb.js:25081:28handleLoadedTexture@src/cocos2d-jsb.js:9154:10initWithElement@src/cocos2d-jsb.js:9086:75set@src/cocos2d-jsb.js:9006:21src/cocos2d-jsb.js:38951:15src/cocos2d-jsb.js:18458:7src/cocos2d-jsb.js:26287:2fireTimeout@jsb-adapter/jsb-builtin.js:2033:34tick@jsb-adapter/jsb-builtin.js:1995:16
Uncaught TypeError: Cannot read property "load" of null
[0]171.u.invoke@src/cocos2d-jsb.js:25081[1]handleLoadedTexture@src/cocos2d-jsb.js:9154[2]initWithElement@src/cocos2d-jsb.js:9086[3]set@src/cocos2d-jsb.js:9006[4]anonymous@src/cocos2d-jsb.js:38951[5]anonymous@src/cocos2d-jsb.js:18458[6]anonymous@src/cocos2d-jsb.js:26287[7]fireTimeout@jsb-adapter/jsb-builtin.js:2033[8]tick@jsb-adapter/jsb-builtin.js:1995
TypeError: null is not an object (evaluating "this._iframe.src")
_dispatchEvent@jsb-adapter/jsb-engine.js:3047:61load@jsb-adapter/jsb-engine.js:2888:36
Uncaught TypeError: Cannot read property "src" of null
[0]_p._dispatchEvent@jsb-adapter/jsb-engine.js:3047[1]cbs.load@jsb-adapter/jsb-engine.js:2888