teredo tunneling pseudo-interface cannot start

hello, yesterday i installed ais 5.0.418. everything is fine except in device manager i have exclamation mark by teredo tunneling pseudo-interface, next to network adaptor. i tried reinstalling driver but it says it’s up to date but cant start? internet works can anyone give me some info on this please? should i un install it?
thanks.
64 bit windows 7 realtek network card.

it’s fixed now, i tried the beta version last night but the sandbox wouldnt work so i rolled back, this may have caused it i suppose. anyway after posting i was told about the latest nvidia drivers braking cards again, so did a system image restore and re installed device manager all ok now.