Some displayed tooltips (not all, only in selected fields) are constantly flashing, as if there is some constant refreshing going on.
One example is below (will try to add more).
Steps to Reproduce:
1. Open the Addressbook wizard (via Tools > Addressbook source ...")
2. Press the "Addressbook source..." button on the upper right
3. Wizard opens and then place cursor over one of fields on the right in the wizard (of course with tooltips enabled).
The tooltip displays but is flashing.
User Profile Reset: No
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:53.0) Gecko/20100101 Firefox/53.0
*** This bug has been marked as a duplicate of bug 105433 ***