Rake not executing some tasks, gives "Invoke <task>s (first_time, not_needed)"

I posted a SO question about his issue here. Most of the background is there. Here's the gist:

I have a task called :run that takes one argument, :filter. Depending on what I pass as the argument, it will sometimes execute with the trace:

** Invoke run (first_time)
** Execute run

Other times it doesn't execute at all, giving the trace:

** Invoke runs (first_time, not_needed)

Notice that when it fails, the trace says runs and not run even though run is the task typed in the command.

This happens when I run the rakefile in some directories, but not others.

Using:

• ruby 2.0.0p645 (2015-04-13) [i386-mingw32]
• rake, version 10.4.2
• Window 7

Start with the linked Stack Overflow question and reproduce the behavior using the mentioned Rakefile, the :run task, and its :filter argument. Compare runs from the directories where the trace differs, focusing on why the trace changes from run to runs and reports not_needed. Done means the task executes consistently with the expected trace across those directories.