Windows 7 Pro x64 with taskbars at the top of the screen.

On my secondary monitor, the taskbar buttons immediately after upgrading from 3.1.6.6 Beta 6 were showing a small horizontal line one or two pixels tall at the bottom of the screen, like the buttons had wrapped around the top of the screen to the bottom. Minimizing all windows to show desktop did not remove, they were not clickable, closing a window caused one to go away (I had 4).

After screen saver kicked in and unlocking, the button remnants no longer displayed. However, after a minute or two, they showed up again. Locking and unlocking did not case them to go away.

Never mind!

It appears to be an interaction between my secondary monitor running on a VGA connection through an IOGear KVM - every few times the KVM is switched, it draws the right hand monitor 1 pixel wrapped down - happens to the wallpaper when the DF Taskbar is closed.

However, testing the issue did reveal another issue - unplugging and reconnecting the secondary monitor (causing Windows to move all programs to the primary monitor), DF drew its taskbar buttons too low on the primary monitor windows. Sending the Window back to the secondary monitor fixed the taskbar button positions.

Since the maximized windows were also a pixel shorter on the primary monitor, I wondered if the DF Taskbar is a pixel taller than the Windows 7 taskbar?

the DF taskbar is customizable... But as for the default I don't know.