I've read a number of reports that the latest
iPhone firmware update (1.1.3) is causing SMS text messaging problems for some users. In a
thread on Apple's support site, there are more than 200 replied regarding this issue. Apple has
posted a document acknowledging the problem, but has not gone so far to list it as a bug... yet. The document is titled 'iPhone: SMS messages may be displayed in the wrong order when sending or receiving text messages'. It goes on to suggest that setting up the iPhone to receive network time should fix the problem. If you're experiencing this issue, give it a try.