Weird files in project window

Hi, I get these weird files in my project windows. They have the same icon as a script, but they can’t be opened, and their names are long series of numbers and letters with dashes (like a serial number).
I deleted one, and (seamingly) random stuff disappeared.
What are they?

Maybe you have the same problem. I think the strangely named files are be the ones that disappear.

http://forum.unity3d.com/viewtopic.php?t=3864&highlight=permissions+issues

I see. That described my problem precisely.
So they are corrupted prefabs, are they? No need keeping them then.
Thanks.