FN+F3 - lcd turns back on by itself

[emit]

I hit FN+F3 on my T43 to shut off the lcd but it turns back on by itself about 5 minutes later. Any idea whats wrong? Thanks in advance.

[FTC]

Hi,

Most probably it is receiving some input and thinks it should wake up. In my case this happens if I leave my USB mouse connected.. since any vibration produced by cars in the street, subway, etc.. will make the mouse sending some 'minor movement' variations to the notebook.

[emit]

I doubt it because Im using the same mouse Ive always had (logitech mx500) and havent had this problem with my previous laptops/desktops.