Do you have any display control knobs on the back of the monitor? They may just be holes that you have to poke a screwdriver in to turn. Sometimes these controls can get affected my dust, causing the display to wobble.
Bit of a long shot though, as this wouldn't really explain the line you have going up the screen, I don't think. It's more likely the tube is on it's way out, as Cygnus said.
Bit of a long shot though, as this wouldn't really explain the line you have going up the screen, I don't think. It's more likely the tube is on it's way out, as Cygnus said.