no hidden files in "recent documents" - how?

[David Meier <droebbel.melta@gmx.de>]

I am quite annoyed always seeing some of my mailfolders in the "Recent 
Documents" (Kicker / K-Menu), it is really no use like this. How can I change 
it so that it doesn't show hidden files? Using KDE3.1.1a at the moment.

David