The runtime was handling the message lookup correctly in this case, but only as a side-effect of the fallback code from when type-dependent dispatch is not possible. This resulted in a confusing warning message, telling you that you were calling a method with an incorrect signature, when the two signatures that it printed were the same.
This case is now handled correctly, so the warning disappears (unless you really are calling a method with the wrong signature and have TDD enabled).
Imported selector table code frm the Étoilé runtime. We can now make dispatch type dependent with a -D switch. Not enabled yet, but it will be enabled in a warning mode soon - I consider preferable to the existing GNU and Apple solution of corrupting the stack.
David Chisnall
theraven