I have been very impressed by the way xrandr handles external LCD screens, connected to DVI or VGA. But, today, I unplugged my laptop from dock, and than plugged it back in after a while without any preparation before unplugging it!
For a surprise, my usb mounted storage was again there (no idea how :-) and everything worked more-or-less great, except external LCD connected to DVI which was in power saving mode. None of the buttons (including off!) on monitor worked. For a moment my mind glimpsed upon idea of rebooting monitor, but I quickly rejected that silly idea.
So, I rebooted Linux instead. I still wonder how did that usb storage got mounted... since it reported write errors on shutdown it probably wasn't there alltough I saw usb-storage claming device again after I plugged laptop back into dock.
Rebooting laptop was a mistake. My laptop boots nowhere near 5 seconds so I had to wait a longish time while monitor was still in power save mode. Buttons on it still didn't work.
When I started X again, and when xrandr again apparently positioned it correctly above internal LCD, I run off options and unplugged power from external LCD monitor. Right after I plugged it back in, picture was there. In optimal resolution. As it should. I just rebooted my monitor!