Help my samsung fokus s can not download with wi-fi

[orlandovlore]

i heve samsung focus s from at&t but is unlock..and am using te t-mobile servis...
i dont no what t-mobile did with my phone but i can't dowload app from my phone with wi-fi
and shows me this text in the screen.."""there is a problem completing your request. try again later. error code:d0000011"""