Have you tried with different ISP?
It need more clarification about your Internet Connection type, speed, bandwidth, ping time, data loss rate, compatibility with hubpage and ad sense site, operating system condition etc to find out the problem.
But generically, I can say may be something wrong with DNS (Domain Name Service) or firewall of your ISP. If so, you can try different DNS or IP hiding. Easy hide IP, an IP hiding software is most likely to solve your problem. You can try free trial. Download > Install > start > hide and use anything other. Now restart your browser and try the problematic task.