Disable Adblock [and anything similar] for all sketchucation.com AND buysellads.com pages.
Also empty your browser's cache.
Also check that your Firewall is not blocking the sites.
Also Check that you have javascript enabled... and your Internet Options control-panel has no onerous settings that might block things...

Thousands of members successfully navigate SCF and see the very relevant and informative ads that fund its very existence... So it is fixable. [I am typing this in the latest version of Firefox on Win7 so I know it can work !]