Hi,
Just installed Debian Squeeze. In Lenny I was able to run Konqueror as root, when it was needed, but I can't do it in KDE 4.4.5 that comes with Squeeze.
What I did: Alt+F2, then select the app to run as root (tried Dolphin and Konqueror), then check "Run as a different user" checkbox, enter the username (root) and password, the application starts but it appears to be run with the same user's privileges, instead of root. No error message that something went wrong, nothing, only that I do not seem to have root's privileges.