I am new to Ubuntu. Several days ago, I finally installed Ubuntu in my Acer Apire 5520 and updated to 8.04. However, the screen resolution is 640x480. I enabled the restricted device for Nvidia GeForce 7000M, but still in low resolution mode.I downloaded and installed from nvidia website. After running the nvidia-settings, it still provided low resolution 640x480. Would anyone tell me how to upgrade the resolution? Thanks.