Message reply going to wrong number

[amyelizabeth_7]

Today I replied to a text message I'd gotten. When I checked my messages for some reason it sent to a completely random number not even saved in my phone. I'm really worried about this, should I be or is this just a bug?

 

[bab2010]

iOS 5.0.1 iPHONE 4S? if so and you are using it with GSM card, try to remove the sim card and load it back again, do it without turning off the device.