EXT4 Store Batch Sync Exception

单条数据删除sync正常，批量删除时循环sync发生异常，不知该如何解决？

CONSOLE:
POST http://localhost:8080/Accordion/userinfo/delete.action?_dc=1341979966300 500 (Internal Server Error)

CONTROLLER CODE:

[code="js"]

deleteUser: function(button) {

var record = this.getUserInfoGridPanel().getSelectionModel().getSelection();
store = this.getUserInfosStore();

Ext.Msg.confirm("提示：", "..",function(button) {
      if (button=="yes"){
        for(var i=0;i<record.length;i++){
                store.remove(record[i]);
                store.sync(); // Batch Sync Exception
        }
      }
});

}

[/code]

for(var i=0;i<record.length;i++){

store.remove(record[i]);

store.sync(); // Batch Sync Exception

}

这个代码改成
for(var i=0;i<record.length;i++){

store.remove(record[i]);

}

store.sync(); 试试看看