Publish in debug mode but compiler removes code inside #if debug

Question

I'm only publishing in debug mode to test on my local machine and I was hoping the '#if debug' mode would work so that I could test features that I don't want in production yet.

When I publish in debug mode the web.config still has

<system.web>
    <compilation debug="true" targetFramework="4.0">
</system.web>

but when I use reflector on the project's dll the code that was like this

#if debug
    PlaceHolder1.Visible = true;
#endif

is non-existent. I figure the compiler has removed it.

NOTE: I'm NOT talking about a build, I'm talking about publishing. Doing a debug build works as I expect it to with the code above still present

Is this expected behavior? Is there a way to get the compiler to include those bits of code when I'm publishing in debug mode? Am I going about this all wrong?

Update: In response to @dash's comment my Package/Publish Web settings are:

Answer 1

C# preprocessor symbols are case-sensitive. Try:

#if DEBUG