EpsonDX4800 scans only gray shadows

I have a problem with my epson dx 4850 (scanner and printer). installation on opensuse 11.0 just went fine, printer is working. today i tried to scan a color picture with xsane. i hear the scanner unit running but the result is poor: only aside is the real picture, the rest is in a shady gray, nothing to see. gutenprint driver for this epson dx 4850 is installed with yast. could it be that the scanner unit is malfunctioning? and how could i test this?
i would appreciate any help, thanx.