[MonoDevelop] Understanding ifdef's in monodevelop

[Charles Krinke]

I have a VS2008 project with a .SLN and .csprog file that compiles
until the first "using SlimDX" where it errors in monodevelop.

#if DirectX

using SlimDX;

using SlimDX.Direct3D9;

using SlimDX.Windows;

using System.Threading;

#endif


I can see that DirectX appears defined in the .csproj file but not the
.sln file. I comment out in the .csproj file the references to
DirectX, close and re-open the .csproj file and rebuild and the error
is the same.

That is, DirectX appears to be still defined. The behavior is the same
if I open the .sln or .csproj file and do a rebuild all.

What am I missing here? How can I undefine DirectX in monodevelop?

-- 
Charles Krinke