I have an unlocked mifi and last weekend I bought a 3 sim card, one of those small ones with an adapter. Worked ok, tried it Sunday night, no network (well at one location) tried it at home, it woked and then drops no network. I now see on the display Y antenna, wifi, envelope(mail)1 , battery,, Mobile partner cant connect.device not found!!! I can see it from my pv wirless. Changed cable, no difference... Thoughts?