[El Ha$oN]

i was having this same issue for a couple of weeks. After searching i found a quick fix for it by installing an app from the marketplace called SMS time fix.

But after playing around and checking all my settings. I realized that at one point in the Date & time section of settings, that the time was not set to automatic.

So i uninstalled the sms time fix app and started sending test text messages after putting time setting to automatic and everything is back to normal and no more problems.

To put the time on automatic(use network-provided values) go to:
Settings-------Date & Time------and make sure Automatic is checked marked.

hope this helps =D>