Java SE (Java Platform, Standard Edition)

I have a problem that doesn't happen to all users of our application. We have our application launch via Java Web Start. We have a JNLP file that is dynamically generated for each of our customers. Once the application is installed they receive updates for the existing jar files that are listed in the JNLP file. The problem happens when we update the JNLP file "href" and "resources" to point to a different location which has the newer version of our application. It seems some people update to the latest version and others don't. This is with the same version of the JRE installed of different machines within a local network.

I have verified that the JNLP file is correct and valid by using JaNeLA.

I have even verified that the updated JNLP file is being retrieved by using Wireshark to capture the network traffic.

It seems that the java installation on some machines basically ignores the new JNLP file that is sent and continues with the existing one. We even have the update settings set to the following:

<update check="timeout" policy="always"/>

Is there something I am missing in regards as to how Java Web Start works when it recieves an updated JNLP file?

Any help would be appreciated

Thanks,
Mike