The Windows 7 desktop stretches across the three monitors, as expected, and I added the game to the Eyefinity configuration settings, so that the extra-wide resolution is available in the game's video settings. I can change the resolution in the game (Unreal Tournament III) to stretch across all three monitors, and that seems to work (i.e. the game menus all look okay). However, when I launch into the actual game play, the resolution drops significantly, even though it is still stretched across the three monitors. It also gets somewhat choppy.
Is something not configured properly, or is my system simply under-powered?
Its most likely the game itself. UT3 is an older title. Check the widescreengaming forums for information on the exact title to see if there is a fix for the stretching issue but most likely with a title that old you wont find too much support for multi-monitor setups. I'd also recommend trying another game to make sure the issue is the game itself.