When I try commit or reject changes for "dirty" Store I recieve java.util.ConcurrentModificationException.

Code:
com.extjs.gxt.ui.client.store.Store.java
...
  public void rejectChanges() {
    for (Record r : modified) {    // iterate through "modified" list
      r.reject(false);                 // in this method fire: store.afterReject(this);
    }
    modified.clear();
  }
...
  protected void afterReject(Record record) {
    modified.remove(record);    // change "modified" list !!!!
  // in next iteration through "modified" list in rejectChanges() I recieve ConcurrentModificationException
    fireStoreEvent(Update, RecordUpdate.REJECT, record);
  }