Um, if the editor is someone you know, you should check with her--just ask "Everything OK? I noticed you unfriended me and if you're just out of reading time or whatever, no worries--just wanted to check in and make sure I didn't say something rude" or something. I suggest this because a couple years ago a friend's feelings got REALLY hurt when it appeared that I had unfriended her--when in fact it was just a stupid LJ glitch.