This occurs when the scheduled backup time is not set or set to 0. Klok essential always thinks its time to run a backup. This is an issues that has been fixed with the Klok 2.2.2 update.
To correct the problem:
Close Klok.
Then open the preferences file which is stored in different locations depending on your OS.
Windows XP:
C:\Documents and Settings\[User Name]\Application Data\Klok2.
Windows Vista/Win 7:
C:\Users\[User Name]\AppData\Roaming\Klok2.
Mac OSX
user/Library/Preferences/
Inside that folder you will find a file called config.xml. If you open that file in notepad, you will see that contents of it. Inside it, you will find a line that contains this:
<backup-delay>0</backup-delay>
Change the 0 (or if there is any value less than 1) to a 7 and save your file. Then reopen Klok and you should be back in business.