Yeah, this happens to me all the time. I'll start a post at work and then get busy and have to come back to it. I've learned by now that when this happens I just have to copy and past the text, back out and repost. From my experience, some forum software allows the admins to set the time it takes for a post to time out. If this is possible in UBB (never used it,) I'd like to see the setting changed.