1150GHz? Did you manage to steal one of them Graphene chips off IBM's research facility and reball them into your N900?

On a more serious note, 1150MHz on the N900 works on very few devices. And even on those that do work, you'll need to push your voltage up to the maximum, which burns battery life like crazy.

Leave your overckock at 850MHz. It'll run a lot better and stabler that way.