Failed to list files in /camera

[Donn]

> X Error: BadDevice, invalid or uninitialized input device 168
> Major opcode: 145
> Minor opcode: 3
> Resource id: 0x0
> Failed to open device
I'm pretty sure that is not related to your camera. 

It's an error that will appear on the console, no matter what you run. I think 
it's telling you that an input device in your /etc/X11/xorg.conf file is 
being referred-to but is not available. It's most likely the sections to do 
with the wacom graphics tablet. You can either edit your xorg.conf file (post 
it and we'll try to help) or just ignore the error.

hth
/d