I'm planning to create a media center with Raspberry Pi. For that I would like to attach a 500 GB USB hard disk drive that I already own.
Right now, I'm trying XBian, but I already tried Raspbmc and the same thing happened. I'm using an 8 GB SD card for the OS, a 1.0 A cellphone charger to power the Raspberry Pi, Samsung LCD TV for display (HDMI).
From what I read I need a powered USB hub in order to power the USB hard disk drive, so I bought one. I bought a Soyntec powered hub with seven USB ports (Model Nexoos 395, just for the record).
If I connect the keyboard into one of the Raspberry Pi's USB ports and the hub on the other (without anything plugged into the hub and without powering the hub), everything works well. If I add a 16 GB pendrive in the hub (wihtout powering the hub), the Raspberry Pi recognizes the pendrive and works fine. If I unplug the pendrive from the hub, and I plug the hub's power cord in order to get it powered (without plugging any usb device, just the hub to the Raspberry Pi), everything works well.
The problem comes when I try to plug anything into the hub after is powered. If I plug either the pendrive (which worked in the hub before powering the hub) or the USB hard disk drive, the screen starts to "flicker" (black screen, back to normal for a second, black screen, and so on).
So the problem seems to be if I plug something into the hub when the hub is powered.... because if the hub is not powered, it seems to work. But if I don't power the hub I won't be able to use my hard disk drive which is my objective.