Disappearing scripts

Yesterday I had two occasions when a script inside an object disappeared.

The first time it happened, I thought it was my fault. I had an object with a script and several sound effects. I wanted someone else in my group to be able to work on it, and therefore decided to set it to the group. Unfortunately at the time I wasn't wearing an active group. The object's texture immediately disappeared, as did the script inside it (which I had been working on for two days).

The second occasion was later in the day, when I was moving several objects with scripts inside. In the case of one of these objects, I discovered its script had vanished. So it appears I might not have been entirely to blame in the first case.

Has anybody else experienced anything like this?

I got few "Script not found in database" messages yesterday when I tried to work on my stuff. Oh joy oh joy