I recently have been getting this problem. No new hardware, no devices around the monitor to make it get interference. Also, it only happens if the game had been running awhile. Today for the first time, I was sitting in a chatroom on battle net and it locked up for a minute or so with a beep. Then it started to work again and jumbled up like it had done lately. Any help would be appreciated. I have a Nvidia Geforce 4 TI4200 Tornado by INNO3D, AMD Athlon XP 1600+, 256 DDR 2100, Shuttle AK32 motherboard.