Forms edition

I'm having some bug here:
This is the situation, I create a node using the great hierrchical select module ( this node has 3 taxonomies, one is using your module), everything works fine. Now, I want to change one term but this term is not the one that is selected with the hierarchical module, so I edit the node, switch the term, but when I submit the node, the term is not changed. Any ideas why?.