Default JDK to be installed with MQ4.2 installer is JDk1.5.0_12
If the User's system has a Higher version of JDK then the installer
on the Summary page shows :
Install is incomplete 

User will notice that JDK1.5.0_12 was not installed . However MQ is installed & configured

However this Summary Screen does not provide sufficient information on why JDK1.5.0_12 was not installed

If user checks the commandline from where the installer was launched then the User can get the information that :Newer JDK , greater than JDk1.5.0_12 is installed on the System

It will be helpful to users if this information is displayed  on the Summary Screen

See screen shots
These were taken on a Linux RH5.0 system
Posted Date : 2008-03-10 19:08:04.0

Here's the output from the installer

SEVERE: Cannot install package
RPM installation failed. Package=/.automount/jpgserv/root/disk11/builds/nightly/ws/solaris-sparc/dist/mq4_2-installer-linux/Product//UNIX/LINUX/X86/2.4/Packages/jdk-1_5_0_12-linux-i586.rpm Exit Code=1 Output=  package jdk-1.6.0_04-fcs (which is newer than jdk-1.5.0_12-fcs) is already installed
        package jdk-1.5.0_12-fcs is already installed
 : Cannot perform installation task Package=jdk-1_5_0_12-linux-i586.rpm
Posted Date : 2008-03-14 17:01:21.0

Seems to only happen on linux.

Transferring to OI for evaluation.
Posted Date : 2008-03-14 17:01:21.0

use jdk.rpmoptions

N/A