Today I tried to scann as root from the x terminal and got the famous "no devices available". Got a shock but I unplugged and replugged the scanner and this time it worked again like yesterday. Scanned a document to the desktop. Upside down it went
Tried as user "jv" and I got : Failed to open device `genesys:libusb:/dev/usb4:/dev/ugen0':
Error during device I/O
As jv I can use both the three gear icon in gnome to start xsane and the xterminal as $.
As root I cannot use the gnome three gear icon as the popping up window disappears immediately.