Could you please help me?

problem : After several times trying to login to Google.com/talk, after signing in, it will redirect me to http://support.google.com/chat/?hl=en&topic=1725163 . 

tries : i have tried to clear cache, clear history, (there is no button to delete database) on the safari settings and even rebooted my phone - tried this method http://productforums.google.com/forum/#!topic/mobile/avvkvyIhvmU

platform : 3GS version 5.1.1.

What may be the problem?

Thanks for your time