I don't know what happened last night but I was texting a friend all the way until about 11:45. Went to send another text just after midnight and noticed my entire text history was gone! Previous to this, all my sent and received texts were in the message folder. Now for some reason, I can't see any of my outgoing texts and they're not auto saved in the history anymore. The second I click send, the message disappears and there's no way to check and see if it was sent or not. I've checked options and made sure that the hide sent messages was unclicked and it was. So what the heck is going on?
maybe it was a surge in the service of your provider being it was new years eve, a lot of people calling each other at the same time around the country and the world.
Sounds like you're out of memory on the phone. The 8300 only has 64MB of app memory and that goes quick. Deleting messages was the way the older OSs on those models would try to gain some back.
My boyfriend & I had a similar problem on our bbs, on mine in kept saying "network unavailable" when I would text someone and show that it didn't go thru, but my sister says she got the same text from me 12 times. On my boyfriends bb he got the same error message plus lost his text history.