If you're seeing Zebra, please report over to [url=http://www.bungie.net/en/Forum/Post/71904739/0/0]this thread[/url] to report information and help Bungie target what's going on with that error.
You can find the instructions and information for GRAPE on this page. [url]http://www.bungie.net/7_Error-Code-GRAPE/en/Help/Article/11743[/url]