Hi,
OpenDNS should help prevent redirects.
Make sure you have the *settings correct* in System Preferences / Network - Advanced -DNS
Use only these numbers.
208.67.222.222
208.67.220.220
More about OpenDNS here:
http://www.opendns.com/start/
The numbers above are for the Basic / Free plan.
This could be more of a cookies issue, then redirects.
From your Safari menu bar click Safari / Preferences then select the Security tab. Click: Show Cookies. Delete any cookies for sites you have problems accessing.
Quit Safari (Command + Q) then relaunch Safari.
Carolyn 🙂