Resharper + NUnit Test Working Directory

I have following scenario.

ProjectA is a simple WPF application which uses a relative connectionString (defined in app.config) something like "data source=.\Database\database.db"

ProjectB is a class library for my UI Tests which uses Specflow + NUnit + Teststack.White.

When my Specflow test tries to launch the WPF application, the WPF application crashes because the working directory is some Resharper directory and not the build directory of the UI Test Class Library and the relative connectionString can not be used because there is no database.

My question is how can I resolve that problem and keep the relative connectionString in my app.config ?