Long time reader, first time poster. I've had my 8gb 1.1.3 iphone for a few months now, unlocked, jailbroken and working well for the most part. My problem is that for some reason or another certain people just can't get my text messages, one person can't get mine, but I get texts from them, and with another person it seems random, where a text will go through either to or from me. But very rarely, so rarely in fact I think it only happened once, otherwise nothing. Beyond this I have no problems with text messaging, other than the time stamp problem that I have never really bothered to fix.

My sim card is probably more than 4 years old...would a newer sim have any chance of fixing this? If not, any other ideas?