I have found a little bug when changing the style of a node (I am sorry if the terms are not correct since I use the french version of FreeMind)
In the menu called "Présentation" in french (5th one from the left) that I would translate as Layout there are Two options at the top for modifying the design of a node "Bulle" et "Branche" which I have found in the XML of the mindmap to be translated as "bubble" and "fork" after the tag STYLE.
When you apply a style to a node, either bubble or fork, you change all its children to the same style (I suppose this is normal) but if you select the parent of this node and apply another style, the style does not cascade to the children.
I am not sure I am clear so here is an example of this.
The first parent is named FatherNode, and as two children named child1 and child2 (which may have children too).
Then you set child1 to have bubble style.
When you set FatherNode to bubble then back to fork, child1 stays as bubble.
Cascading does not work.
Removing all the STYLE=... directive from the xml restores the standard functionning of the switch.
PS: Sorry if this is an already known bug, I haven't found it when searching