Post dissappear after updating

Hi,
I created a post a while back, and keep updating it as I go. Yesterday I found out that when I save the post, it would just show up as empty on the main page, altho I can see the HTML code in the edit menu. If I use teh Visual tab to save the post, it will just return an empty post as if I deleted my post. I found out that if I limit my post to a certain extent, it would show. Is this a wordpress error? I also suspected that it might be the data sent to MySQL had timed out, but as the data IS shown if I load the page in HTML edit mode, I doubt that was the problem. Anyways, thank you in advance