I am using SVN 3875 (24/09/2010).
Spec: Linux, Sun Java 1.6.0_20-b02 64bit, 8 GByte RAM, Core2Quad 2,66 GHz (Q9450)
My nodes have a lot of whitespace around the contained text. When I use the feature that highlights the nodes connected to the current one, I (sometimes) need to move the mouse cursor over the node's border line or the text contained in it. The feature does not trigger when I have the cursor just inside a node. This makes the feature less usable. It seems you can trigger this behaviour by moving the cursor into the node from inside, then over whitespace, then over text and then over whitespace again.