Panel - specific issues
Repairing Options on the Panel
Right clicking the panel at the bottom or top in Ubuntu will give you the option to add/remove panel items and change panel settings. Through this process; various applets display themselves; which leads to many customization options.
Common issues
Missing Windows Buttons on Task Bar
A common issue is missing task windows on the bottom panel. This issue is solved by adding the Windows List applet.
Missing Network Status
Another commonly encountered problem is when a user inadvertently drags the default network status icon off the top task bar. This is remedied by right clicking the top task bar and adding the Network Manager applet.