Dell Community Forum users like Vishnu M. issue reported this issue. We've identified the issue and corrected it with the latest BIOS revision posted yesterday, version A10, which will correct the symptoms.
Again, users that have encountered this issue can click here to download the BIOS.
There have also been reports of this issue on the XPS M1530. The next BIOS revision is being tested now, and will also correct the symptoms. That revision is slated for web posting in June.