I've got 512Mb of kingston DDR400 CL3 ( KVRx64c3a/512 ) . I've bought another KVRx64c3a/512 ... When i put both of them together windows is not running up. When i put one of them ( any ) system goes up, everything works. You could say its because of bad slot in my mobo. But when i put A-data ram + kingston ram everything works.. Dunno what's wrong... HELP PLEASE