Funny, you just posted this today. This happened to me yesterday, and I had no idea what it meant. I dismissed it, and everything seemed alright until I had to close the form and reopen it. I was completely locked out of my Developer 11 database. I tried several things to get back into it, and finally had to delete the data and start a new one. Now I have tons of things to redo from scratch. Now I'll know if it happens again.