"Go to definition" is grayed out, but I can find the variable through a search in the same file

Question

I am debugging C # well in vs2008 SP1, .NET Framework 3.5.

In the .cs file, I have this code:

internal protected bool Refreshing{  
        get { return refreshing;}  
        set { refreshing = value;}  
}  

elsewhere, in the same file, I have this statement:

if (Refreshing) return;  

When I debug and right-click “Update”,
“Go to Definition” is grayed out.

These are not just properties for which Go to Definition is grayed out,
these are also methods and, possibly, everything else.

It seems that "Go To Definition" is especially useful during debugging; more than just looking at the code.

Any ideas why?