I wasn't able to reproduce your issue - setting the name from the code-behind works on my machine. Can you create a small project that is just isolating the issue and send it to me so that I can take a look.
By the way, why do you need to set the Name property in the code-behind? As you can read on MSDN, "The name provides a reference so that code-behind, such as event handler code, can refer to a markup element after it is constructed during processing by a XAML processor
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