If I have both on I can't acess the internet the 3g+ is constantly on as if fetching data but nothing online works.. If I turn off cellular data everything works via WiFi and same goes of I turn WiFi off, cellular data works well..
delete the following reg keys
you may have more than 1 entry, delete them all.
power off the phone to ensure the reg is saved, power on and restart the phone.
This may also help those who are unable to connect with wifi and 3g on at the same time..
---------- Post added at 05:04 PM ---------- Previous post was at 05:02 PM ----------
if you are still having issues try swapping the sim over to one of a different service provider, even if it doesn't work.