Welcome to WebmasterWorld Guest from 188.8.131.52
I will enter a short list of URL's, save, and when I come back, they are gone.
I also noticed that my earnings (just on search) dropped 90% around the time this "bug" appeared.
Anybody else having this problem with Adsense for Search?
BUT, that said, I KNOW there are bugs with the refinements tabs and where sites appear and don't appear. So, ya, it's possible you hit a bug. But I haven't seen that specific one.