Possible causes - MTU set too high/low. Malware interfering with your hosts file or DNS settings. Malware has changed your browser security settings. ISP having problems. Sites mis-identifying your browser.
Isn't this kind of issue possibly to do with the wrong subnet mask, in one's router config?
Highly unlikely - unless you have been assigned a fixed IP address, this will be provided by the ISP along with IP address and default gateway. Of course, if the ISP has screwed up something this simple, it's time to change ISP!
Ping the list of names:
www.bom.gov.au
www.heraldsun.news.com.au
www.manlyairportbus.com.au
www.dictionary.com
www.grisoft.com
www.ingdirect.com.au
www.myway.com
www.theage.com
Do they resolve to an IP address and do you get a response?
SD