The problem is *not* the enhanced "for" loop. It is the fact that you are changing the collection while you are iterating through it.
Unfortunately, the enhanced "for" loop hides the iterator from you, so you don't know this is happening. The correct way to remove an item from the collection, while iterating, is to use the iterator to remove the item. However, this means that you can't use the enhanced "for" loop.
So based on what Henry told I concluded is that the invisible iterator is performing the task for getting the objects in Object elem while at the same time in the SOP I am trying to modify the collection(q.poll()). [ November 23, 2006: Message edited by: Sanjeev Kumar Singh ]