Checkbox not checking inside div in Firefox

Weird problem. I don't know if anyone can shed some light on this? I have a checkbox inside a div. It works fine in IE but not Firefox. I have to click the space around the checkbox that is occupied by the div (sort of like a label) for the checkbox to tick on and off. Directly clicking the ch开发者_高级运维eckbox does not show it as ticked on or off, even though in firebug it is showing that it is in a checked state and an unchecked state.

Only in FF does this happen.....

I think this is a bug in firebug. Disabling firebug will stop this behaviour happening.

I had a similar strange thing happening with radio buttons. Disabling firebug fixed it.