stop automatic drop down menu scrolling?

[chimp1cards]

I've got a HP Compaq tc4200 tablet. Somehow did a keystroke combo that caused
all
my drop down menus to start scrolling like maniacs. Anyone know how to stop
the insanity

Thanks!

 

[3c273]

Just a guess... maybe the "page down" or the "down arrow" key is stuck.
Louis