[CCleaner does not clean "Show Your Top Sites" in FF 50.1.0]

Any workaround?  This is the first screen you see when a Firefox tab loads, your internet history with thumbnails.  Even though CTRL-H shows it is cleared by CCleaner, the history still appears in opening a new tab.

 

Essentially CCleaner is not clearing all of Firefox history.

[CCleaner does not clean "Show Your Top Sites" in FF 50.1.0]

"Show Your Top Sites" is the most frequented items in your internet history when you open a new tab.

 

If you start a new tab and "Show Your Top Sites" is checked the thumbnails disappear after being Cleaned but the URL's still appear under each blank thumbnail.

 

Internet history including cookies is checked and does get cleaned but not for "Show Your Top Sites" history.

 

Windows 7, Firefox 50.1.0,  CCleaner 5.25.5902

 

thx