Version: (using KDE 4.3.0) Installed from: Ubuntu Packages Kde 3.5 had an option to raise an autohiding panel when moving the mouse to a specific screen corner, while the panel keeps hidden when the mouse touches the edge of the screen or panel off the corner. I heavily used this feature to avoid raising panels when I accidently touch a screen edge, while it is still very easy to raise the panel by pushing the mouse to the respective corner. I would love to see this feature reappear in future 4.x versions.
*** This bug has been marked as a duplicate of bug 185318 ***