Font Navigator not uninstalling fonts properly.

Hi Corel Team,

Need some help with Font Navigator. I am trying to uninstall fonts and I keep getting this message:

"The following cannot be uninstalled because its in use... You will need to reboot"

Its happening when I try to uninstall any font I select. Is there something wrong with FN or do I have to keep rebooting every time I try to uninstall a font. Any advice on this would be greatly appreciated. Thanks