This guy, and associated/similar tests, has/have become unstable.
Prior to build #339 they just worked. From #340 onwards they sometimes
pass, sometimes fail.

According to the manifests we publish as part of each build the change
from 339 to 340 is just

< Files (cmm.119)
---
> Files (cmm.120)

which seems completely unrelated!

If it weren't for the fact that everything in the test happened in the
context of the main World thread (whatever its proper name is), I'd
think it was a race: the tests consist of
* perform a UI action
* check that the UI's showing what we expect - that there's a list
morph somewhere in the UI whose contents match some list.

I've tried debugging these, and they're annoyingly non-deterministic.
I've often found that rerunning the test - run it til it fails, rerun
the failing assertion - makes the test pass!

Any thoughts?

frank