Track a session to a Buffer

Hi All, I just had a case where onstat -u returned a 'B' as the first flag in the second column for over 100 sessions. The wait column for all the sessions had the same hex number. Is it possible to track down the session that is causing all the others to wait? I tried onstat -s and onstat -g lmx and onstat -k and onstat -g ath none did the trick. All help greatly appreciated. Thank You, Zev Berezin