Boeing Dreamliners supposedly have a software fault that causes them to loose power due to the generators going into failsafe mode. After the plane has been run contionusly for 248 days. So the FAA has ordered them to be shutdown for an hour every 3 months.
http://www.nzherald.co.nz/business/news/article.cfm?c_id=3&objectid=11443089
But seriously, you can keep a Windows computer running for over 3 months. (and lots of servers out there that run without restarting for far longer). Yet they cant write code for a plane that can run without needing restarting. Surely they should have done more testing.