I created a test case here: http://gist.github.com/585048 to demonstrate the issue.
Basically passing a 'context' object to addObserver does not seem to get passed on to the callback,
the 'non context' signature (e.g. fooDidChange: function(sender, key, value, rev); ) is being called even if a context is passed (and should be calling this signature: fooDidChange: function(sender, key, value, context, rev); )
What version is this for? 1.4 or quilmes? Also, has this worked for you in the past?
quilmes. I'm not sure if it worked in the past, didn't encounter it. Can someone verify that the tests fails for them as well?
Test appears to fail in master/1.4. However, unless it's a regression it won't be fixed for 1.4. It's on the radar for 1.5 though.