Hi there first post on the forums, I figured this would be the best place to ask my question.

I've got a bunch of damaged iPhone 4's some of them arrive unactivated so one of the first things I do is activate them with iTunes to see what kind of working order they are in.

To this end I purchased a brand new Vodafone microsim the sim has no credit on it and if I leave the sim in the phone eventually I'll get a txt from Vodafone telling me I don't have enough credit to send a txt message which is odd because I haven't sent any txt's.

It's happened with all the iPhone 4's I've activated and left the sim in the phone for a bit.  I can't tell what the contents of the txt is or who it's going to.  Only thing I can think off is that there is some kind of secondary activation with Vodafone for the microsim?

Can anyone shed some light on what this mystery txt is?