Nokia 5800 wifi problem!!?

[Junnabett]

I lately bought a nokia 5800.I was able to connect to my talktalk router via wlan.the prob is after i downloaded some apps i cant connect.Ive tried uninstalling the apps but the phone still trys to connect to 'fnjt' whatever that is.I went into app mngr but even after selecting talktalk it still wont connect.what is fnjt and how can i resolve this issue