Sessions Hang When Not Being Traced/Unhang When Being Traced

[Tom Pall]

Anybody seen this before?   Running 8.1.5.0 on Solaris.  We have a third party product written in java which runs for a certain amount of time then hangs.  I don't see any locks or waits for the applications sessions.  This does not happen if I put sql_trace=true in the init file and bounce the database.  I can unhang and hang the application sessions using ORADEBUG EVENT 10046 TRACE NAME CONTEXT FOREVER, LEVEL whatever/ORADEBUG EVENT 10046 TRACE NAME CONTEXT OFF.   I've searched Metalink's bug database and haven't found any bugs that apply yet.