Hi Chris. We found a problem with WeakOrderedCollection in Pharo which may cause problems in Magma users in Pharo. Basically, once a WeakOrderedCollection needed to #grew, it stops being weak because the internal array was replaced by a Array instead of a WeakArray. (WeakOrderedCollection new instVarNamed: 'array') class ->>>> WeakArray (WeakOrderedCollection new grow instVarNamed: 'array') class ->>>> Array So....I can imagine that some applications running magma may grow a lot due to this bug. Just to check whether someone is having this bug or not, you may want to execute: WeakOrderedCollection allInstances select: [:each | (each instVarNamed: 'array') class = Array ] if you have instances, then that's a problem ;) To fix it, you can fileine the changes of the issue tracker: http://code.google.com/p/pharo/issues/detail?id=4596 and then you should fix the already created instances. cheers ps: I have no idea how much Magma uses WeakOrderedCollection, but I thought it was just worth it to raise a warning. -- Mariano http://marianopeck.wordpress.com