Thanks for taking the time to contribute to the jQuery project! Please provide a reduced test case on http://jsFiddle.net that reproduces the issue experienced to help us assess your ticket!

Additionally, test against the jQuery (edge) version to ensure the issue still exists.

I (i.e. someone else) also have the problem.

I created a jsFiddle here (click the checkbox a few times):

http://jsfiddle.net/6cKQw/

It worked before, not in 6b1.

I do not know how to test with the "jQuery (edge)" version. Perhaps this should be explained somewhere in the "how to file a bug" section :)

The checked attribute doesn't actually change and is not actually present in your fiddle. You are thinking of the property. You can use .prop("checked") or .is(":checked") to see if a checkbox is checked. The latter is preferable.

http://jsfiddle.net/6cKQw/1/ should be what you want

Interesting, thank you. Stupid mistake on my part. But I had been using it since a year ago, across my entire application, most likely because I had read somewhere that I could do it like that. And that was in fact correct, at least until jQuery 1.5.2.

So I'm just making this last comment to prepare y'all for a bunch of people that may have partly broken applications as soon as 1.6 is released, if they automatically adopt it :) I realise that this is 'their fault', because they, like me, used a 'wrong' approach, but to them it may feel like something that's not backwards compatible. It's something that (erroneously) worked, but no longer does.

Ha! I'm a prophet. (see above comment, and 1.6.1rc notes)

(.. I should however have registered before actually writing that comment)