Jason Snell is having issues with his save sheets in Yosemite:

This morning I tried to save a file in BBEdit, only to discover that I couldn’t see half of the save sheet—it was so large, it went off the bottom of the screen.

It turns out—and thanks to Jon Gotow of St. Clair Software, maker of the excellent Default Folder X, for the answer to this—that there’s a bug in Yosemite that causes a sheet to grow taller by 22 pixels every time you use it.

If you’re experiencing the same issues, check out the rest of the article to learn how to fix it.