Tente Reinstalar O Mu seguindo esses Passos:
http://forum.muaway.net/index.php?/topic/299-reinstalando-muaway-corretamente/
Evitar Lag:
http://forum.muaway.net/index.php?/topic/221-%3Cspan%20class=
Instalar ou atualizar a Placa de Video:
http://forum.muaway.net/index.php?/topic/217-tutorial-como-instalar-ou-atualizar-seu-driver-de-video/
Siga os passos:^^
Windows 7:
http://forum.muaway.net/index.php?/topic/13-%3Cspan%20class=
Evitar Lag:
http://forum.muaway.net/index.php?/topic/221-evitar-lag/