Building utf-16 project files

I am using team City 5.0.1 (build 10715) and I have several csproj files set as utf-16 they build fine under Visual studio 2008 and msbuild but when I run them on a team city agent I get the following error "error MSB4025: The project file could not be loaded. There is no Unicode byte order mark. Cannot switch to Unicode." Is there some configuration I am missing to the build agents? What am I missing?