Behat hangs when trying to download some files with Sahi driver

[arnaugm]

A simple scenario that clicks on a link which opens a pdf and then goes to another page, makes behat waits until a time out exception is thrown when using Sahi.

Feature: download a file
  In order to resolve an issue downloading a file with behat
  As a developer
  I need to create a failing test

  Scenario: Try the download of a pdf with Sahi
    Given I am on "http://twig.sensiolabs.org/documentation"
    When I follow "PDF"
    Then I am on "http://www.wikipedia.org"
      Command execution time limit reached: `_sahi._navigateTo("http://www.wikipedia.org", true)`

1 scenario (1 failed)
3 steps (2 passed, 1 failed)
1m7.534s

That doesn't seems to be a problem when using Selenium2

Feature: download a file
  In order to resolve an issue downloading a file with behat
  As a developer
  I need to create a failing test

  Scenario: Try the download of a pdf with Selenium2
    Given I am on "http://twig.sensiolabs.org/documentation"
    When I follow "PDF"
    Then I am on "http://www.wikipedia.org"

1 scenario (1 passed)
3 steps (3 passed)
0m9.935s

I've tried with Firefox and Chrome and the behavior is the same in both.

It's probably related to the type of file to download as the problem si also present here

Feature: download a file
  In order to resolve an issue downloading a file with behat
  As a developer
  I need to create a failing test

  Scenario: Try the download of a file
    Given I am on "http://pear.behat.org/"
    When I follow "2.3.5"
    Then I am on "http://www.wikipedia.org"
      Command execution time limit reached: `_sahi._navigateTo("http://www.wikipedia.org", true)`

1 scenario (1 failed)
3 steps (2 passed, 1 failed)
1m6.76s

but not here

Feature: download a file
  In order to resolve an issue downloading a file with behat
  As a developer
  I need to create a failing test

  Scenario: Try the download of a file
    Given I am on "http://symfony.com/download"
    When I follow "http://symfony.com/download?v=Symfony_Standard_Vendors_2.2.1.tgz"
    Then I am on "http://www.wikipedia.org"

1 scenario (1 passed)
3 steps (3 passed)
0m6.988s