Multiselect problem

[eluser]Marcel Karras[/eluser]
I think the problem I have doesn't have something to do with the form_dropdown(...) function as the HTML form output is okay. Also the multiselect behavior works as expected but the POST request will only contain a string instead of an array containing all selected elements. If I change the name of the dropdown to "installation[]" I get a string with the value "Array" as POST result. So where does CodeIgniter add the selection result variable (should be an array but is a string) into the POST? Seems to me if something alters the $_POST before I get rid of it.