Slower connection in upgraded 11g database.

One of our development database was recently upgraded from 10.2.0.4 to 11.1.0.7 on HPUX 11.31 ia64.  After the upgrade, we have a mix of 10.2.0.4 and 11.1.0.7 databases on two different homes on the same server.  In the testing of 11.1.0.7, the developers have found that initiating a connection to the 11g database takes, on average, about half a second longer than on the 10g database.  This is simply connecting through sqlplus with either a bequeath connection or through a tns alias.  The developers are using timex to check the elapsed time.  See below for the bequeath example.  If I