I cant log into any online accounts, such as Facebook, GMail and others.
i managed to log in once in my life time to all these accounts, but none after that.
normal surfing is okay tho.

the phone will say things like 'wrong pass','unable to authenticate do you want to connect without SSL'

these things still happen under a working WiFi on my phone, and a working Access Point.
As for the wrong pass, i have typed correctly for at least 4 times with no avail...
any ideas?

i hv searched a post that says delete the internet accounts in itunes and relog in again...well...so i synced with my Outlook for my GMail, but the phone still gives 'wrong credentials'

Try this:

chmod -R 777 /private/var/mobile/Library/Cookies

Either in your iPhone terminal, or SSH

after that restart, and clear cash history and cookies then restart safari (worked for me ) :p