P: Dual monitor support: ability extend the first monitor to the second

I was using Lightroom 4.3 but discovered that the slideshow module would not load with two monitors in use. I rolled back to 4.2 and the problem is remedied. I would like to be able to use Lightroom 4.4 with two monitors (OSX 10.8.2) and extend the first monitor to the second. Thanks.