I have a PowerMac G4 running OS 10.4.1 and lately have been having difficulty accessing certain websites. If I try to access these sites, either via Google or my favourites list I get "Safari can't find the server" message. I find this happens even with Firefox, and it's always the same sites. Apart from my problems detailed above my ISP works fine. Is there something I could do to rectify this problem, or is it something that needs to be sorted out by a qualified technician?