I am having a problem with my Geeetech GSM shield, which I am connecting to an Arduino Uno. I am trying to use it to send a text message but every time I try executing the code, the text message is sent once ans then stops sending because the SIM card I am using breaks down in the sense that it stops sending text messages even on a regular phone (it continues to receive messages and calls, though). Has anyone encountered problems such as this one? Any advice would be greatly appreciated!!