Let's say I start working on a task and open 5 editors (and do not close them), then I deactivate the task, after the task has been deactivated I close all open editors. Now when I reactivate the task I expect all the editors to be opened once more. (The context focused filtering in the Package Explorer works fine though).
I have Eclipse 4.2 I20111007-1625 (latest I build) and Mylyn 3.7.0.I20110928-1200 (I installed the latest weekly snapshot)