Uploading a word .doc file in Silverlight 4, which is already opened by the Word application

Question

Currently, I'm using a Generic handler like receiver.ashx & openFileDialog to select a single file from my desktop and Upload it onto the Server . The Uploading works fine. My Silverlight 4 app. is currently, running in default mode and NOT  in OOB mode.

But I get an exception, when I try and Upload a file ( say for e.g. a word .doc file ) which is already open by the Word application. This is causing me a lot of grief. I use file.OpenRead() like in some of the articles published here. I googled about this issue and there are lot of people talking about the same issue, But none of those suggestions have fixed the issue till now.

I thought, someone might have come across this problem already, since this is one thing a good QA person would never miss. If you have resolved this issue earlier,  pls. give me some pointers.