This problem occurs only if you have installed both a 32 bit JRE and a 64 bit
JRE on the same computer.

1. Install 6u43, 32 bit on Windows 7 64 bit

2. Install 6u43, 64 bit on Windows 7 64 bit

3. Copy a customized, user specific deployment.properties file to
   <User Application Data Folder>\Sun\Java\Deployment\deployment.properties

   The deployment.properties file has been attached to this report
   (it has been renamed to deployment.properties.before)

4. Launch any Java Web Start app using the 32 bit Java Web Start
   for example
   "c:\Program Files (x86)\Java\jre6\bin\javaws" test.jnlp

5. Now, the 64 bit entries in the user's deployment.properties are missing
complely!

   The deployment.properties file has been attached to this report
   (it has been renamed to deployment.properties.before)


Conclusion: The User-Level deployment.properties file should keep all the
entries that have been entered manually even if the customer has installed
both 32bit and 64bit JRE, because the purpose of the User-Level deployment
file is to customize runtime behavior for Java Web Start. See also
http://docs.oracle.com/javase/6/docs/technotes/guides/deployment/deployment-guide/properties.html