This is a super minor issue, but I fall for it every time!
When the "open project" dialog is open and you click on a project, sometimes the list of projects scrolls slightly up. Because of this, double clicking the name of a project (if you haven't already clicked on it once to select it) tends to open the project above it. After the first click, the list shifts so that a different project is under your mouse, and that is the project that ends up opening. This only seems to happen when you have scrolled down in the project list.