Normal users have difficulties installing javafx2 in combination with java (even non-normal users)

I had created, and deployed, a small application on my webserver. It took me some time to get it running on my computer, afterwards I posted a message for others to try.
Currently, 3 out of 8 were unable to install the combination of Java 1.6.32 and javafx 2.1. Which is odd, since some others can.
It appears different, at least Java, installations are causing difficulties.
What I found yesterday was some inconsistency with respect to the software installed. I had 1.7.0_04 and 2.1 installed, then the app wanted to download Java en JavaFX 1.7.0_03 and 2.0.2, respectivily. Hereafter, java, and FX, wanted to be installed, they installed 1.7.0_04 and 2.1.0..
I'd really like to use JavaFX because, from the development environment, it looks really promising. But I do NEED 'normal' user to be able to install Java and JavaFX fluently, otherwise, I'd have to program it in another language. Which would make me sad.