Forum Sidebar Collapse Button

[FooKaa]

Hi,

Since updating to 4.2.0 and also updating my theme im just noticing that my side bar on the forums no longer collapses when you click the button.

I have disabled all plugins and hooks and it still does not work, then i tried it on teh default theme and it DOES work.

So im assuming this must be a theme related issue ?

Any ideas please chaps....