I've read all of the other posts about this monitor but I haven't seem the same exact issue which is why I'm posting. I have a Samsung Series 9 Ultrabook NP900X4B running Windows 8 with a mini hdmi to vga dongle. I tested the same laptop and dongle at work with a VGA Dell monitor and had no issues; I plugged in the cable and immediately saw the extended display on the external monitor. At home with the SA300 I'm getting the flashing screen on the external display and a blank screen on the built in display. I had to break up the videos for resolution.
http://www.youtube.com/watch?v=9VsNmk6lyd4
http://www.youtube.com/watch?v=ugNINJsFwqg
http://www.youtube.com/watch?v=9VsNmk6lyd4
http://www.youtube.com/watch?v=ugNINJsFwqg