FPS fluctuation.

Was running Graphics on default, everything was fine, in act 3 cruel now and am beginning to get serious fps drops which usually end up in deaths, also things like after big graphics changes ingame the client stops working. Not sure whats causing this.
http://www.pcworld.co.uk/gbuk/hp-spectre-xt-13-2100ea-13-3-ultrabook-silver-17056528-pdt.html
That's my laptop, didn't really think i'd get a problem playing on that laptop but meh, let me know.
Thanks for your time.
P.S having long loading screens too, with the only thing in the background is skype, and i'm not in a call on it.