The action seems to be working as expected here, could you send the command line arguments that FinalBuilder is generating so we can see what’s been sent to Visaul Studio?
i.e.
Running C:\Windows\Microsoft.NET\Framework\v2.0.50727\MSBuild.exe with parameters : /t:Build /logger:“I:\FB6Branch\FinalBuilder\FinalBuilder.MSBuild.Tasks.dll” /noconlog /p:Configuration=“Debug”;Platform=“Any CPU”;DefineConstants="_RELEASE=True";Optimize=False;AllowUnsafeBlocks=False /v:normal “C:\Users\paul\Documents\Visual Studio 2008\Projects\ConsoleApplication1\ConsoleApplication1.sln”