I play Mafia Wars, a Zynga game via Facebook. When doing a clickthrough to MW from FB, browser performance (IE, FF, Chrome) all are very slow, with continuous time-outs, partial or incomplete screenloads, or complete failures. Consistent on all three browsers, and across three different PC's using both Win7 and Win8.
Hi-speed netaccess, 50/25 FIOS, and speed checks run great. Verizon finds no line or net problems and i recently replaced my router as part of troubleshooting. No effect.
Other applications/sites aren't affected.
When I disable the Norton 360 Smart Firewall, access speeds up markedly. Still not perfect, so occasional timeouts or partial refreshes, but MUCH better than with firewall turned on.
How do i fix this?