External hard disk can be detected, but can't be read. Please help!

Hi everyone,

I am using Mac OS 10.7.5. And my Buffalo external hard disk "Mini station" acts weird all the time with the Finder, But it returns to normal after I have restarted my Macbook Pro every time. But this time, I can't read those contents anymore.

My Macbook Pro detected my external hard disk but after I have tried to read the contents inside (even use Get Info), the Finder quitted itself and the whole desktop becomes blank and keep flashing out a box repeatedly "Restore Windows - The application "Finder" unexpectedly quit while trying to restore its windows. Do you want to try to restore its windows again?". But I can't click any button in this box. Except this issue, everything is still working fine. After I have pulled away the usb cord of the external hard disk, the Finder gets back to the normal, everything is back to the normal.

Fortunately, this external hard disk is working fine with another macbook. So what would be the problem? I have checked that it's not a cache issue. I have restarted and shut down the Macbook Pro several times. But It's still not working. How can I fix it? Thanks.