I've found that currently Firefox 6.0 is incompatible with JRE 6 Update 26. On the other hand, Firefox 6.0 is indeed compatible with Java SE 7, but Java SE 7 is not yet available on java.com. In fact, I've found that with Java SE 7.0 occur currently some issues, because it's impossible to use websites with Java applets.
Is it not far more useful, that the download of Firefox 6.0 will offered earliest with the completion of Java SE 7.0 for end users?