I have had this issue but I can confirm it is nothing to do with Plus! (or indeed with WLM) because it also occurs sometimes when using Trillian for Android, which connects to Facebook via Jabber (or whatever the protocol for it is). Obviously an issue on Facebook's side.
Facebook chatting - by Tylerohwhat on 08-26-2011 at 07:09 AM RE: Facebook chatting - by matty on 08-26-2011 at 10:55 AM RE: Facebook chatting - by whiz on 08-26-2011 at 12:27 PM
