tec, i am unfamiliar with macs or the safari browser. maybe disabling any extensions or add ons you might have? or as iddee said i would start by trying a different browser, like firefox, to see if the browser is the issue. i have helped others who were using internet explorer who had experienced a myriad of quirks, and seemed to clear up once they switched to using firefox.
let us know if that solves the problem for you.