question marks on safari

Do you have any Safari Plug-ins installed? If you do update them or temporally disable them through Safari's Preferences it might help.

Also what Network DNS (System Preferences->Network pane, Advanced button, DNS mini-tab) are you using? Consider using either OpenDNS or Google Public DNS and it might help.

Lastly make sure your Flash player is updated because them problem might be Flash.

One more thing, does this same same happen at other sites?
This is along the same lines as Satcomer's response. It appears that you are accessing the Web with only guess-access on your router. If this is the case, then you need to find a Wi-Fi connection with full-access.