Strange: all of the sudden the touchpad's "left-click" (i.e. the double tap) AND the left click buttons above and below the touchpad have stopped working. Right-click is fine. Touchpad navigation is fine. I even reinstalled the drivers...nothing.

Could it really be a hardware problem if ALL three left-click options (two buttons and the touchpad) don't work? I doubt it...

Any suggestions?

(PS: on an Inspiron 4150...and yes, I booted in safe mode. No luck)