cant touch back on collection view page

## motivation

This test is flickering on CI simulators:

```
Scenario: I want to see the collection view
Given I see the views that scroll home view
And I go to the collection view page
Then I can go back to the scrolling home view

Timeout waiting for elements: view marked:'scrolling views home'
```

### notes

* only on the 'master' toolchain **CONFIRMED - reproduced locally**
* ~~possible bug in touch_transition?~~
* ~~possible bug on view with collection views?~~

### Reproduce

#### ~~Demonstrates that back button + touch_transition + collection view is not working.~~

* http://ljs-jenkins.ngrok.com/job/briar-pr/22/cucumber-html-reports/

####  ~~Demonstrates that back button + touch_transition + collection view is not to blame.~~

* http://ljs-jenkins.ngrok.com/job/briar-pr/23/cucumber-html-reports/

####  ~~Demonstrates that a long sleep after waiting does not help~~

* http://ljs-jenkins.ngrok.com/job/briar-pr/24/cucumber-html-reports/

#### It is the Accessibility Inspector blocking the touch. (>_>)

==

![2014-08-13_21-08-27](https://cloud.githubusercontent.com/assets/466104/3911003/719fb766-231d-11e4-8a01-b0ab07040671.png)


==