I'm always experiencing this Google "dances" too. Sometimes I'm even losing my supposedly no. 1 position for my own domain name and get buried until the nth or whatever pages. I begin not to care about it and most of the times I noticed that my ranking goes back to normal. Just keep adding content and let Google worry on its own.
Don't lose your hope, sooner or later Google will fix their bugs - till then, make more side-projects.