Publishing web app with advanced pre-compilation options set to merge throwing issue due to custom attribute in AssemblyInfo

I have a rather strange error. I am trying to precompile an Asp.Net application. From Advanced Precompilation Options, I selected Merge all pages and control outputs to a single assembly

and typed in a name for the build.

If I specify this parameter, I get an error during posting because of a custom attribute in AssemblyInfo.cs

. Errors copied below:

Error   239 The type or namespace name 'CS' could not be found (are you missing a using directive or an assembly reference?)    Properties\AssemblyInfo.cs  4   7   Deploy
Error   240 The type or namespace name 'MyAssembly' could not be found (are you missing a using directive or an assembly reference?)    Properties\AssemblyInfo.cs  40  12  Deploy
Error   241 The type or namespace name 'MyAssemblyAttribute' could not be found (are you missing a using directive or an assembly reference?)   Properties\AssemblyInfo.cs  40  12  Deploy

      

        
        
        
      

    

If I remove the attribute it works. If I leave the attribute but don't Merge all pages and control outputs to a single assembly

check but chooose Do Not merge

it works.

Any ideas why this is?

Also, does it offer any performance advantage between the parameters Do Not merge

and Merge all pages and control outputs to a single assembly

?

I am using the latest .Net 4.5 and VS2012 update.