Custom 404 page renders as plain text in Chrome

I have a site running in SharePoint 2010 (14) mode on a SharePoint 2013 farm. We have developed a custom 404 page and have set the FileNotFoundPage property of the SPWebApplication object to the file name located in the 14 hive. The custom 404 page has been saved with UTF-8 encoding without BOM. iisreset has been issued to all Web Front End Servers and this works fine in IE, Safari and Firefox. However, Chrome is still rendering as text instead of text/html.

Thanks for your help in solving this.

Kurt Opel

Kurt Opel SharePoint Consultant @knaopel