I had not heard of this happening. In the future I will start copying and pasting my post content into a file to store it before I post too. That's good advice regardless it seems.
We work hard to post content, so it is definitely disappointing to have it vanish!
Did you post from your phone or a computer? I know it shouldn't matter much, but I've had weird sync issues while using my phone.
Was using the PC. I had a weird experience where I put a order in on the market on my phone, and the money was no where to be found on the PC, it vanished from my wallet and the market. When I went on my phone to the market, it was still there, and when I canceled the order I was able to access the funds from the PC again. Some kinks to work out!