CIS summary page may show the wrong number of unrecognised files or files which are now verdicted as safe by CIS may have got stuck in submitted files. This can occur due to a bug in past versions of CIS.
First put your computer into safe mode by rebooting then pressing F8 every second or so immediately after reboot.
Then delete C:\Program Files\COMODO\COMODO Internet Security\database\pending.* files if you have a problem with unrecognised files
Or delete C:\Program Files\COMODO\COMODO Internet Security\database\submit.* files if you have a problem with submitted files
Reboot again.
The files will be created again on reboot or after a new (real) unrecognized or submitted file appears!
With many thanks to RickRev and Bambis who developed this fix.