When you set the panel to "hidden" and yoo set the pointer on the edge of the screen the panel doesn't show up. You have to set the pointer on the very edge of the panel (the section that's visible when it's hidden, a bar of 2 or 3px height) to make it appear. This is more like an obstacle because you have to be very precise with the mouse.
This usually happens when you have set the window manager option to switch virtual workspace when the mouse reaches the end of the screen. Does your setup have this option selected?
Unchecking the option to switch workspaces at the end of the screen solves the problem using xfwm4, but it doesn't work when you're using compiz as a window manager. Is this still an issue of xfce4-panel?
(In reply to comment #2) > Unchecking the option to switch workspaces at the end of the screen solves the > problem using xfwm4, but it doesn't work when you're using compiz as a window > manager. > > Is this still an issue of xfce4-panel? Well, it is not something that we can solve, really. When the panel and the window manager both want to get evens for the screen edge, the window manager usually 'wins'.
Closing old report