[WIN] Workflow Percentage shown incorrectly

The bug consists in showing NaN% instead of workflow percentage.
The bug happens when hiring a new staff member while there is a new project in developing (tested with every stage).
Assigning the new staff member to an area doesn’t increase his workflow and its contribution to the project is none.

Here is an image to explain the bug:
http://i44.tinypic.com/30xityu.png (I’m a new user, I can’t post the image directly through the forum)