This bug surfaced in 4.4 and is still present in 4.4.2: When I minimize an app by pressing the 'recent apps' button, it sometimes (but not always) will not show up in the list. I have to press 'home' and 'recent apps' again to make it appear. Sometimes I have to do this twice, which is extremely annoying. This happens seemingly randomly, making it impossible to reproduce the bug. So far I have not found a single report on this issue. I'm seriously out of ideas what could be done about it, a factory reset did not alleviate the problem.