What happened with Lion and iWork, who messed up?

I used to love my Mac with Leopard and working with my iWork apps. specially keynote... until my upgrade to Lion!

Now all I get is the rolling ball, it is slow, I cannot save as well as before, now every presentation I made is locked or if i make a change is a nightmare... what happened. Who messed up a nice working application and how do I fix my this?