I'm having this same issue on my system. I have a Radeon HD5770 with the newest drivers and noticed the hanging issue near the start of November when I updated the drivers. My system is a Windows 7 64-bit with a Phenom II X6.
When I ran my release configuration in debug mode in VS2008, I noticed that on the list of loaded .dll files (Modules), the message "The module did not load at the default load address" appeared on the icon for the following .dlls in my project: sfml-window.dll, sfml-graphics.dll, atiadlxy.dll
Even more so, SFML.net programs that I hadn't even touched in a while have the same problem as the C++ game project that I had been working on frequently.
I guess I'll try to downgrade my drivers to 10.10 or below.