[development] form api changes? $_POST values handling changed?

Hi everybody, I'm working on different modules for some project. Two of them has a search feature that basically create a form on a callback hook. Then simply use the values of the form to do some searching on the nodes.. Yesterday I aligned my one week old cvs install to current head and then both of those modules stopped to work. So I'm asking.. There has been form api changes or $_POST values handling changes??? Thanks, Fabio