This is a weird problem. Usually 2-3 hours after starting my computer, either in console mode or x-window, a white cursor block (about 10% larger than actual cursor block size) appears in the center of the screen.
This block has a fixed position and cannot be covered up by anything. I've tried starting and running only the fewest init processes necessary and a new debian install on another partition. Sometimes when switching from the console to x-window the block will disappear for a few mins, but always returns.Any clues where to look? -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~