I group my session browser window by username most of the time. If I select a user and expand that username on the LHS (top), I see perhaps nine sessions. If I click on the Sessions tab (RHS, bottom)), I see only five sessions.
I believe this is related to Oracle view V$SESSION_CLIENT_INFO having a negative value for the SERIAL# which makes the detail (RHS) query not grab all the rows in the join.
I saw some TOADWorld message entry (http://toadfororacle.com/thread.jspa?threadID=28250) that mentioned removing three columns from the display, but I don't see any way to do that in my release.
Missing an outer join when connecting to v$session_connect_info.
Click on the small icon in the northwest corner to open the data grid column selections. Deselect columns: authentication_type, client_chartset, and client_version.
Issue fixed in version 11.0 The latest version of Toad for Oracle can be downloaded at: http://support.quest.com/support_download/Downloads.asp