Safari Issues

Ive been looking for solutions and although most say the same solutions, it has not worked for me. When I want to access certain sites, Craigslist for example i get the "failed to open page, cannot connect to server etc." error. This happened awhile back when I wanted to read a tech blog and I completely forgot the solution I found.
Ive tried reseting safari, emptying cache, used ClamX, EVERYTHING. Craigslist still won't connect. Tried also changing the DNS servers. NOTHING. I had access to it a week ago. I also looked in the preferences/library to delete the safari plist. But I didn't even see a safari one. HELP?!
Tried Opera and Firefox as well.

 

Im on WiFi. Just curious why would the Wifi/Router only be blocking that one site?