I managed to make SlimServer work (again). Even with the firewall active and in "custom" mode (meaning the ROKU is configured as "allowed").
However, when I want to look at my digipics online, it won't find the Windows Media Connect Server. Some days ago this still worked fine; however only after the first install of the WMC. Since then, no success.
Anybody has an idea of how to make this tool share my (two) folders with all the pictures in it with RoKU? I would really love to look at our wedding pictures on the new LCD through the ROKU!
Thanks a lot for all your help!