Refresh problems

Hi, I'im developing an application that uses DB_DataObject, QuickForm_Controller and Smarty. I've got a problem with the "update" pages, where I need to load the default values (setDefault($def)) to the form. The first time I visit the page it is ok, but if I change and submit something in the form, the next time I visit the same page the default values of the form are filled with the old values (pre-update). And if I reload the page in the browser the problem persists, until I hit return in the navigation bar. I don't know if there is a problem with DB_DataObject, QFC or Smarty. I'm trying this with $force_compile=true (smarty). Do you any ideas to try? Thanks. Regards. Toni.