I think you were blocked by that user. ;o When someone blocks you, you cannot whisper/see whispers from that user, see them, or see anything they say. They might have accidently blocked you, or you may have accidently blocked them.
They also might have kicked you from that group. Maybe they were mad about something?
Good luck. ^^
Well you see, the group wasn't deleted and as far as I know, there person said he didn't block me. I looked at my block list and it's empty so I don't know....
That's strange. o-o Can that user see you and see your posts? I has to be a block.
I's try searching the group in the group tag and see if it shows up. People who've blocked you don't show up on your block list. People you block show up there.