[Pharo-dev] WeakMessageSend is broken?

Assume we have the following weak message send: message := WeakMessageSend

receiver: Morph new selector: #color. 100000 timesRepeat: [ message value ]

If you execute it in latest Pharo and VM you will (almost 100% sure) get DNU. (but it should just return nil if receiver is garbage collected) How can I ensure that it selector is not being sent to nil? http://ws.stfx.eu/6QOWBLQENVIY Am I doing something wrong? Cheers, Alex