You may see your application running on DB2 v8.1 on AIX may "hang", and your app is reporting
myapp:ERROR   2004-05-26 21:36:13.214000 context:?:? [Servlet.Engine.Transports : 2] - 
[IBM][CLI Driver] SQL1224N  A database agent could not be started to service a request, or 
was terminated as a result of a database system shutdown or a force command.  SQLSTATE=55032
 - ?(?:?)

The problem: shared memeory between DB2 and other apps on the same OS is not enough; 
basically, DB2 runs out of memeory for DB2 agents proceses.  To fix, try:
to FIX:
 Set the EXTSHM environment variable by entering the following commands: 

$ EXTSHM=ON 
$ export EXTSHM 
$ db2set DB2ENVLIST=EXTSHM

Ensure: that the EXTSHM environment variable is set each time you start DB2. 
Do this by editing /home/db2inst1/sqllib/profile.env and add or modify the line: 

DB2ENVLIST='EXTSHM' 

Also add the following to /home/db2inst1/sqllib/userprofile: 

export EXTSHM=ON 

Add EXT_SHM to userpofile of DB2.