Version: (using KDE 4.3.2) OS: Linux Installed from: Ubuntu Packages In the KDE Screensaver unlock dialog, the Unlock button is smaller compared to the Switch User and Cancel button. Also, the Unlock button has no icon, which may cause it to be smaller.
I can confirm this issue on Archlinux with KDE 4.4.0.
*** This bug has been marked as a duplicate of bug 244155 ***