Fail Issue: Identified

So, I've figured out why my loaf of bread was such a fail yesterday.  Last night I attempted a loaf of my usual sourdough - the one that works every single time.  It seems my sourdough starter has gone comatose.  I don't think it's dead, as it still smells right, and it still forms small bubbles when new flour and water is added, but it's not reacting and growing at the correct rate.

I'm a bit bummed at the moment, but I suppose this means that now I'll learn how to revive my starter, and then I can pass that info on to you all!  Off to do some research...