I seem to have fixed it for now, there was this strange conversation in my conversation list (down around the time that I updated to 1.3), it had no contact name, and clicking on it would not open that conversation, I pressed and held on that wacked out conversation, choose delete, (not sure if it's a needed step, but I then also deleted the conversation I had with the contact I was having trouble with), then, said contact SMS'ed me, at which point it showed up in my conversations, I opened that conversation once, and it crashed conversations, I reopened it, clicked that conversation again, and it's been working like a champ since (ie back to normal like 1.2, msg is intantly marked as sent, and all msgs show up after closing the conversation), I'll add stuff to the bugs.maemo late tonight or in the morning, but figured that info might help you for now, good luck.