So I jb's and unlocked my sister's 3GS (running 4.0.1) so she could take it over to Spain. She's got a spain sim card installed and it works fine for phone calls. however she does not have a data plan over there so I had her go into Settings --> Network and turn off cellular data and data roaming. However when she does that she says she can no longer surf the web or send/receive email using her phone on her wifi network (even though the wifi signal shows full arches and she's connected to her wifi network). The data only works if she turns cellular data and data roaming back on, in which case I presume she is using her cellular data network and not the wifi network. Any ideas on why this is happening or what she can do to solve the problem? Appreciate any help. TIA.