Windows 7 Task Bar Disappears

[Reno03]

Running Windows 7 with the latest updates on a T400.  This problem appeared with the last week.  

The Taskbar at the bottom of my desktop disappears on its own without a plausible reason.  I have the Taskbar set for "Lock the taskbar" and the Auto-hide function is not selected.  Yet the taskbar goes away without warning.

When I try to find the Taskbar and get it to reappear by moving the cursor over to where it was suppose to be and taking the cursor off the visible screen along the edge, nothing happens.  The little arrow that points up and down in place of the cursor when it is over the Taskbar never appears.  I have also checked both sides and the top of the screen but no Taskbar. 

The only way to get it back is to restart the computer.  Meanwhile I have open IE pages and other apps running with their status on that Taskbar.  What is wrong?  Is there a reset display function or special commands to  bring the Taskbar back?

[Reno03]

Additional observation:  The Taskbar disappears when the computer goes to sleep or hibernates.  Upon waking it , the desktop reappears minus the Taskbar.  No known methods to reinstate theTaskbar seems to work.  As a workaround, I have lengthened the time  before the computer turns off the display or goes to sleep to avoid the inadvertent loss of the Taskbar.   

Is this a power management issue?  Or is something causing the Taskbar to move to the background behind the screen wallpaper?  Suggestions please.

[karmazin]

Hi, my coleague has very same problem. After standby only round "Start button" is visible, no task bar at all.

She has L520.

[karmazin]

Just found out this has probably something to do with screen saver.