Hi,
On each view (Alfa, Betta, Gamma) in the right down corner you have View Menu, by default Smoke and Camers are Widgets, so check "Widgets" from this menu, and if you make a Smoke to be hidden, then check "Hidden Objects" also. Then your smoke will apear.There are keyboard shortcuts for the both functions.
Ctrl+Shift+W is for the Widgets
Ctrl+Shift+H is for the Hidden Objects
Best Regards!
Dian Tuhchiev