iPhone 4 Subway Issues

[MixinJ]

I have an iPhone 4, when the subway goes above the ground, the phone can't seem to reconnect. It goes into "searching" for a while and then goes into "No Service." I have to power off and then turn it back on. Anyone else having this problem?

[daniel28]

Do you have a case on the phone? I know some cases tend to block the signal from reaching the antenna on the iPhone 4.