A user will be "awaiting approval" if he submits an email address in the help desk that is already assigned to someone else. Ordinarily, there is a button next to the user under Configuration\User Access & Roles in order for an admin to approve the user and merge him with the other user that shares his email address.
However, there is a known issue whereby this button can disappear, i.e. if an admin manually submits an email address for the user without using the approval button. There is a database script you can run to resolve this issue and get rid of the approval message. I would recommend contacting support@lansweeper.com to request this script and linking this forum thread in your email.