Jtree adding node strange..

[Robert , doodle]

Hi there,
i have created a tree and filled the nodes from a
simple database.
Ive added a popmenu where i can add nodes
which will be inserted in the database
Now my question
when i left-click a node and add a node it works only
if the parent node does not have been collapsed...
any suggestions why the state of the sub-tree is important
when i close the node and try it again it still does'nt work...