Why would would protected actuals automatically appear in a plan?

[LC]

We have had a few strange occurances of protected actuals appearing in a plan
without a resource actually entering the hours in PWA. We recently had
approximately 1,400 hours appear under an "unassigned" resource dating as far
back as a year ago. The hours are obviously not appearing in PWA since the
resource is "unassigned".

Would the plan be considered corupt as this only occurs with this one plan
on our server?

Thanks for your help.