Taskbar buttons are not centered in taskbar.

The taskbar buttons appear to be misaligned with the taskbar itself. Checking
this out in 17004, it seems there is a painting issue initially. Resizing the
taskbat will cause a repaint that fills in the bottom of the button. When
opening many Command Prompts the buttons ran together, and also did not flow
into the expanded taskbar.

This needs to be checked against ROS Explorer under windows.