i have the same problem with my iiyama 514 22 inch..
i can adjust it, but eveytime i reboot my pc, it's stretched again, like the monitor doesn't save the settings.
i have been looking for a fix for over 3 or 4 weeks, and it's realy annoying, i have to re-adjust my monitor settings everytime i reboot my pc, only fix i've heard of is leaving you pc on standby, but i can't do that.