Just re-did the sheep part of the quest to get more wools on my Ranger, and after clicking on the rope the slot machine immediately freezes around Success. You catch the sheep (though one try only netted me a Green Herb), but you cannot do anything else. Not able to use items on hotkeys or skills. I tried using another rope while it was frozen on my screen still (by double-clicking it in my inventory), and it used it but nothing happened, and I didn't catch the sheep I ran up to.
Nothing to do but relog to character select screen to get it to go away. Then use another rope only to have to relog yet again. I'm just glad you only need 5 sheep...