Occasionally the cursor on my laptop will leap to either the bottom left corner or the top right, though it prefers to go to the bottom left. It occasionally just slowly slides, and sometimes can't make up its mind about which of those two corners it wants to go to. The periods in which it does this can range from five seconds to five minutes.
A mild impact on the lower left corner of the keyboard can cause it to jump into this state, and sometimes severe impact on the right will as well, but it does occasionally do this by itself.
It never clicks, and always goes to one of those corners, so it isn't a remote computer. I can still click when it is like this. Using the ball in the center of the keyboard can let me seize back a degree of control, but the trackpad only works when it's moving slowly.
Restarting does not work, and it's been persistently bothering me as I never know when it will begin.
Does anyone know what could be causing this?
The laptop is a Dell Latitude D820