BizTalk Orchestration Rename Error : symbol xx_message is already defined the first definition is in xx_assembly

One of the weird BizTalk errors that's been around since version 2004 goes something like this:

Error    35    
symbol 'MyNamespace.DataObject' is already defined; the first definition is in assembly c:\Development\Library\MyObjects.dll    
C:\Development\Examples\BizTalk\ObjAlreadDefined.odx    169    50    

This error has been blogged about several times. Example 1 Example 2
The standard "fix" is to remove the C# code that is found at the end of the orchestration file by:

• Open the orchestration in notepad or as XML
• Find (Ctrl-F) #endif // __DESIGNER_DATA
• Delete all of the code found below #endif // __DESIGNER_DATA
• Save and Recompile

Recently, I discovered a critical issue with that fix.
The code that you are removing is the code that allows BizTalk to export that orchestration as a public object. 
So if you use the standard fix, you can't call the orchestration from another orchestration.

I believe that I have found the root of the problem and a much simpler fix.
The "Already Defined" object in my example is a reference object called MyNamespace.DataObject.AbstractDatawhich is defined in MyObjects.dll. This object is used to create a varible instance called DataObject.
If I rename the variable DataObject to DataObject_AbstractData the compile issue goes away.

IMHO, when a Web Reference is added to the project, the orchestration compiler is no longer able to distinguish between part of a namespace and a variable instance of the same name.

So the moral of the story is to make sure your variable names don't conflict with any part of a namespace that in reference by your project. This "rule" goes for any variable.