The problem is the Adapter, I have only the seen this issue about 3 times on these boards. But most generally it's the adapter, Those adapters are hit and mostly miss on whether they work or not. You can try a DP->VGA adapter as they generally have more success.
BTW, Skyroads is Awesome, you need to get the Updated remake called Tasty Static.
http://www.tastystatic.com/
Guess what? It's also supports surround gaming right out of the box.
http://www.widescreengamingforum.com/forum/viewtopic.php?f=56&t=16830&p=165201 - Detailed Widescreen Report