Default [REQ] or question, tap clock in notification bar to open clock app

I'm sure once, recently, I could tap the clock on my pull down notification drawer and the clock app opened. But now it doesnt, have installed things and possibly upgraded my AOSB rom as I dont know when this suddenly didnt work, just noticed it today.
Is there any conflicts or apps that would disable this? or a way to get it back? I run exposed if this helps...