"Briefs filed with the Alaska Supreme Court in Miller v Treadwell reveal that 1,553 voters in the Alaska U.S. Senate race wrote in “Lisa Murkowski” but didn’t fill in the oval next to the name written in. The Alaska Elections Division did not count these votes for Murkowski. However, Murkowski’s attorneys are arguing that they should have been counted."
Rick Hasen has links to all the briefs here.