LinuxQuestions.org - Mozilla 1.6

Quote:

I am continually getting "java not installed" or "java not enabled" when I visit sites that require Java. However, Java is installed and enabled. What can I do to get it to work?
First, check if Java is enabled in Mozilla. To do that, select Edit -> Preferences -> Advanced and make sure Enable Java is checked.
Then, open the Java console to see if Mozilla is selected as program that uses Sun Java. To do that, select (in Windows) "Start" -> "Settings" -> "Control Panel". Double-click on the "Java Plug-in" icon and select the "Browsers" tab. "Mozilla 1.1 or higher" should be checked.
Also, make sure you have a current version of Sun Java installed and that you do not have multiple versions (this is possible) installed. I have heard that Mozilla 1.6 requires the latest version (1.4.2_03) of Sun Java.
Next, in Mozilla type about:plugins in the address bar. There should be several entries for "Java Plug-in" (I count 8, with a lot of sub-entries). They should all say "yes" under the enabled setting.
If you are using Linux, Java does not work if Mozilla and Sun Java were compiled using different compiler versions. If that is the case, get a Java version that has been compiled with the same GCC version as Mozilla. Newer versions of both Mozilla and Sun Java use a newer version of GCC, so mixing either an older version of Mozilla (like e.g. 1.4) with a newer version of Sun Java or vice-versa will not work.

A Java FAQ is also available here:
Plugindoc Mozilla and Java FAQ.

took that from

http://mozilla.gunnars.net/mozfaq_us...#Java_problems

there is more reading at the link.