How come DefaultTreeCellRenderer's behaviour changes when called from different directories ?!?

[Spendius]

Hi,
I use the following lines in a TreePanel class I've written:

DefaultTreeCellRenderer rend = new DefaultTreeCellRenderer();
rend.setLeafIcon(null); rend.setClosedIcon(null); rend.setOpenIcon(null);
tree.setCellRenderer(rend);

to see to it that when displayed, my tree will be as plain as can
be (no icon at all, no default small picture on the line where you
click to expand the node etc.).

When I use this class with a certain app., it works, I get what I
want, the tree appears in a thin black dotted line, with a little
squares containing a '+' sign when the nodes are closed, and a '-'
when they're expanded; but in another app. (I use THE VERY SAME
CLASS, the same .class file) instead of the small square with '+'/'-'
I have the Sun default small picture of a node you see ?, a tiny
circle with a dot in its middle and a little hyphen, and the line
is blue pale.

Anyone can explain me this behaviour ??

Thanks...
Regards,
Spendius