More Administrators show than registered

Hi
so again: I have a blog (mariam-ffm.de) and since a few months an astonishing number of users were registering, with wierd mailadresse. Today I cancelled all of them and also changed my admin-details. While doing that I noticed that there are 4 administrators listed, with the figure 4 in brackets, but really there are only 2.
Does anyone know what this means?
Thx & rgds from ffm