Windows Vista - "JInitiator" Vs "Sun JRE"

Hi folks
we are using Oracle 10g AS. For the client end, we were using Oracle JInitiator without any issues for the client OS Windows 2000, XP.
When the same application was accessed from Vista with JInitiator - IE 7 got closed automatically. Then problem was overcomed when IE 7 replaced with Mozilla Firefox or higher. But, when we installed Java standard edition J2SE JRE for running other Java based applications, then this application is not working with firefox because of the JRE installed.
Latercase, we have configured the Oracle 10g AS for running the application with J2SE JRE at client system. Then it was possible that other Java applications as well as our application can be accessed with J2SE JRE with IE 7 in client system (vista OS), for few weeks only. Now, in the same system, when we access the application with J2SE JRE, it takes 3 mins open a form from the main screen.
But if we remove J2SE JRE and install JInitiator and connect the application with Mozilla Firefox, the application works fine and opens the screen in 3-5 secs.
1) Is it possible to use both JInitiator & J2SE JRE together in Vista for running Java based applications & Oracle 10g Applications?
2) Why is the difference, when the same application opened with JInitiator takes 3-5 secs to open a form, but J2SE JRE takes 3 mins for the same action?
Please help.
B. rgds

I believe this is normal - see Mike Shaw's comment on Steven's blog post
You may open an SR to confirm.