I am running dual monitors on mine, without issue, using mHDMI-to-DVI and DP-to-DVI adapters. I am using Windows 7 and latest drivers posted on Intel site. I just replaced the mHDMI-to-DVI adapter with a mHDMI-to-HDMI adapter and (then) a HDMI-to-DVI adapter and it continued to work fine. While I do not have any, I have in the past seen mHDMI-to-HDMI adapters that are absolute crap and do not work properly...
Hope this helps,