One of the drawing tools in my toolbox is yEd.  It’s great for drawing relationship diagrams, particularly if you want to have them automatically re-swizzled.  I choose yEd over a regular mind mapping tool like Xmind because it allows multiple relationships between a node.

Like every drawing program I’ve tried, yEd has it’s quirks too.  Here are a few things I’ve discovered that might help you.

Another frustration with yEd I wish I could solve for you is the middle scroll wheel mouse behavior which zooms the screen in and out, instead of scrolling the page like any other applications you’ve ever used.  It has the power to drive you crazy and there is no way to change it.

Here’s a simple tutorial for using yEd if you’d like to learn more about using it.