Steps to reproduce the issue:

Create a menue item with a list of all contact categories.

Expected result:

You will exptect a translation in the tooltip box, when you hover with the mouse over the numbers after the category name.

Actual result:

In the tooltip box there is only this string COM_CONTACT_NUM_ITEMS, and not the translation.

System information (as much as possible):

Joomla! 3.4.5 testenviroment without any extention.

Additional comments:

You will find the string here: components/com_contact/views/categories/tmpl/default_items.php