capybara-webkit broke after latest Yosemite update ( april 2015 )

I have found that a lot of my cucumber features fails in my current RoR project after installing the latest Yosemite upgrade !? Changing from webkit to selenium seems to fix the problem but I have to keep using webkit.

It just looks like capybara-webkit have trouble clicking buttons and doing stuff he was doing before...

My setup is :

• ruby 2.1.1p76


• Rails 4.1.4


• OSX 10.10.3


• capybara-webkit 1.5.0

Any cue ??

Thx