No signal while "Roaming Only"

[avgas]

I'm using the stock sprint Rom, with the SprintCleanup cab, and I just found out that the "Roaming Only" Regedit is included. However, when I select the Romaing Only option, I get no signal what so ever. I left it in roaming and drove across town and could not pick up a signal, Im pretty sure there are other networks in my area. Anyone had this problem? Thanks