CAL usage report discrepancy

We are using a terminal server to send content to five terminals. The users are in the active directory on a domain controller.

A CAL Usage report was generated. The number of "installed CALs" is 6 but the number of "CALs in use is 7". I think this is causing problems because sometimes  some of the terminals are locked. Is it possible to reduce the number of"CALs in use" to 6, so that it would match the number of installed CALs.I am guessing that this might alleviate the issue.