Created Unassigned: MediaFoundationReader reads less data on Windows 7 (on Windows 8.1 - OK) [16453]

Have got strange result of using MediaFoundationReader to extract audio on Windows 7 64-bit.

Actually, I use MediaFoundationReader for extracting WAVE data to temp file like this:

```
using (var reader = new MediaFoundationReader(sourceFilename))
{
WaveFileWriter.CreateWaveFile(copyFilename, reader);
}
```

After that I read WAVE data with WaveFileReader:

```
using (var sourceFileReader = new WaveFileReader(sourceFilename))
{
Console.WriteLine("Length:\t\t{0}", sourceFileReader.Length);
}

using (var copyFileReader = new WaveFileReader(copyFilename))
{
Console.WriteLine("Length of copy:\t{0}", copyFileReader.Length);
}
```

On Windows 8.1 I get the same data lengths, but on Windows 7 copy has end-trimmed data.

Is there bug in NAudio or Media Foundation on Windows 7?

Test project in attachment.