After performing an upgrade ( s10_50 -> s10_51) I found the following
pkgchk -n errors for SUNWj5dmo:

pkgchk -n SUNWj5dmo
ERROR: /usr/demo/J2SE/demo/jni/Poller/LinkedQueue$LinkedNode.class
    modtime <01/20/04 01:31:18 PM> expected <11/18/03 11:09:07 PM> actual
    file size <602> expected <620> actual
    file cksum <33380> expected <34358> actual
ERROR: /usr/demo/J2SE/demo/jni/Poller/PollingServer$Consumer.class
    modtime <01/20/04 01:31:18 PM> expected <11/18/03 11:09:07 PM> actual
    file size <1331> expected <1342> actual
    file cksum <11772> expected <12477> actual
ERROR: /usr/demo/J2SE/demo/jni/Poller/SimpleServer$ConnHandler.class
    modtime <01/20/04 01:31:18 PM> expected <11/18/03 11:09:07 PM> actual
    file size <1210> expected <1218> actual
    file cksum <7463> expected <7772> actual
#



extract from install_log

WARNING: quick verify of </a/usr/demo/J2SE/demo/jni/Poller/LinkedQueue$LinkedNode.class>; wrong size.
WARNING: quick verify of </a/usr/demo/J2SE/demo/jni/Poller/LinkedQueue$LinkedNode.class>; wrong mod time.
WARNING: quick verify of </a/usr/demo/J2SE/demo/jni/Poller/PollingServer$Consumer.class>; wrong size.
WARNING: quick verify of </a/usr/demo/J2SE/demo/jni/Poller/PollingServer$Consumer.class>; wrong mod time.
WARNING: quick verify of </a/usr/demo/J2SE/demo/jni/Poller/SimpleServer$ConnHandler.class>; wrong size.
WARNING: quick verify of </a/usr/demo/J2SE/demo/jni/Poller/SimpleServer$ConnHandler.class>; wrong mod time.

Installation of <SUNWj5dmo> was successful.



looks similiar to bug #4450497