Caching of resources is impacting some of the functionality related to client auth scenarios while running the applet and JAWS applications. If we are trying to do some validation from the cached contents then behavior should be same across all the applets and as well with JAWS applications.
Steps to reproduce:
1) Import jitu.p12 from following location into your browser keystore. We are going to try this scenario on IE browser since Firefox has some other JSS libraries dependencies which is going to make things bit complicated
http://sqeweb.sfbay.sun.com/deployment2/jitu/plug-bug/jitu.p12

Save this certificate somewhere locally on windows machine and import it into the IE keystore as follows:
- IE> internet options> Content > Certificates
- Under certificate window , try to import client certificate jitu.p12 into personal keystore. Password is "changeit"

2) Once cert is imported , select it under the Personal tab and go to Advanced settings. Make sure that client and server authentication options are checked

3) Now try to load the following applet
https://mossad.sfbay.sun.com:8443/clientAuth/tests/Test.html

Accept all the warning and applet should get loaded fine

4) Close the browser
5) Open Java control Panel and disable following options
Advanced Tab > Security > Use Certificates and Keys in browser keystores

Now try to load the same applet again. With earlier releases it failed to load since after unchecking the above mentioned option applets are not going to read the client cert sitting inside the browser keystore and try to look the certificate under JRE/deployment key store.
With 6u18 applet is getting loaded fine but JAWS application are still having the old behavior i.e. they will fail to load. One can use the following jnlp to see the behavior with JAWS component
https://mossad.sfbay.sun.com:8443/clientAuth/tests/BAT.jnlp
Now clear cache and try to load the same applet again this time applet will fail to load.
So with resources getting cached, either we should make applet fail to load on lines of JNLP application or we should make JNLP application launch successfully