try in a Pharo-1.0-10515-rc3 image :

|set|
set := Set new.
Collection withAllSubclasses do: [:aClass |
	set addAll: aClass methods
	].

It will raise an exception telling: "MessageNotUnderstood: ByteSymbol>>analogousCodeTo:".
Indeed, in the code of CompiledMethod >> = , the message 'analogousCodeTo:' is send to a 
symbol.

I opened an Issue:

http://code.google.com/p/pharo/issues/detail?id=2185