Hello, > I think this must be mcs specific, as the reported *.cs file comes with it: > > serge /usr/local/src/mono/mcs-0.26>locate *.cs | grep StreamReader > /usr/local/src/mono/mcs-0.26/class/corlib/System.IO/StreamReader.cs > /usr/local/src/mono/mcs-0.26/class/corlib/Test/System.IO/StreamReaderTest.cs Maybe you have two mcs installed: one in /usr/bin/mcs and one in /usr/local/bin