Vanishing content with frames

[racechef1957]

Sometimes while doing various tasks I must brush against something and all items on the screens vanish except for the frames they were in. Moving the mouse cures this and returns things as they were. This has happened many times and I can't nail down how I am causing it. I have a Microsoft Wireless 4000 Comfort keyboard with mouse, model 1045. I am prepared to destroy and replace them