Google Talk and firewall

[Q] gtalk installed successfully but cannot connect to google service?

[try]

• chk windows firewall setting (although gtalk installation will automatically change firewall setting to allow gtalk to pass in the normal case)
• chk IP router firewall setting

[Reason]
My Vigor2910's object/group CSM set block rule to prevent google talk, web msn, yahoo messenger, ... only msn and skype are allowed