screenshot of context
This is a follow up to https://bugzilla.wikimedia.org/show_bug.cgi?id=30807
The behavior has indeed improved after the fix mentioned in the latest comments there.
However on Safari 5.1.7 (Mac OS X), it is still not fully resolved. I have attached a screenshot. The blue highlight shown in the screenshot corresponds to the input element wrapped in the div button, as the safari element inspector understands it.
My button is only clickable in the area where the blue highlight and the div of the visual button, overlap. This means that the bottom 20% of my (visual) button does not behave as a button.