What setup your hosts file with so many entries.
The hosts file (http://en.wikipedia.org/wiki/Hosts_file#Ad_filtering) works by avoiding DNS lookup for the entries in it. "Blocking" is done by mapping the relevant domain name to 0.0.0.0 or 127.0.0.1 IP addresses.
Either do away with the hosts file (back it up first maybe) or unblock the "blocked domains" by removing the entries for those domains. Pull out the domain name for the images you want at Toms Harware Reviews from the domain name in its "src" value in the html code.