Hello, I am encountering a weird problem and I couldn't find a fix or even an explanation so I figured out maybe someone here encountered it before. I have a summer '09 Macbook pro that I mostly use in clamshell mode (connecting to my screen with the DVI adaptor). Sometimes when I try to wake up the computer from sleep, it gives a signal to the screen that will then exit sleep mode but then the macbook pro goes back to sleep. I guess it doesn't give enough time to the display to change resolution or whatever. On some occasions it comes up with a black screen, forcing me to reboot (even disconnecting the display doesn't switch the internal LCD back on). Sorry if the explanation is kind of confusing, I do not know how to describe it better. Anyone encountered this problem and know a fix? Thanks!