23" ACD flashes magenta intermittently

My faithful old 23" Apple Cinema Display (clear acrylic enclosure) has started intermittently flashing a magenta cast on the entire display. It must be a hardware issue, since screen shots taken during the flashes do not exhibit the magenta cast. It happens every few minutes or so, with the color cast lasting between 1 and 20 seconds each time.

Is this a common problem? Is it more likely to be a fault in the display itself, or the Apple DVI->ACD adapter I use with my MacBook Pro?