I have been using Coopermine for almost a year and have never had any problems. I am the administrator. Today, I logged in with the same username and password I have always used and did not see the configuration tabs. I noticed that I was in Member Mod and clicked to go to Adm. mod but it would not take me there. I stay all the time in Member Mod even though I logged as administrator.
Clear your cookies in your browser, then log in again - this should send you to admin mode. If this works, never leave admin mode. If it doesn't, do as suggested by board rules, posting rules and common sense: post a link to your gallery for a start.