Smart Cache is cool and all, but have you tried forcing a render?
Smart Render Cache isn't smart enough. Using Render in Place is NOT a solution. Far too often I'm staring at an effect waiting for the system to decide to render it blue so I can play it back in real-time, and even sometimes when it's blue it doesn't play smoothly the first time

but what we really need is a way to just select any clip, or clips, or range, and hit a keyboard shortcut that forces that selection
to render immediately.
Final Cut does this and it's one of the only things I miss.
(that and the magnetic timeline; don't @ me bro)
-Joseph