I've installed java as explained at plugindoc, and my about:config looks like this (below), but any java applet site will not load the applet. There is a column in the about : plugins page that says suffix, but no suffixes are displayed. Could this be the problem?

Thanks for the help. BTW, I'm running Debian/Etch 2.6.18-4-486

Java(TM) Plug-in 1.6.0-b105

File name: libjavaplugin_oji.so
Java(TM) Plug-in 1.6.0

MIME Type Description Suffixes Enabled
application/x-java-vm Java Yes
application/x-java-applet Java Yes
application/x-java-applet;version=1.1 Java Yes
application/x-java-applet;version=1.1.1 Java Yes
application/x-java-applet;version=1.1.2 Java Yes
application/x-java-applet;version=1.1.3 Java Yes
application/x-java-applet;version=1.2 Java Yes
application/x-java-applet;version=1.2.1 Java Yes
application/x-java-applet;version=1.2.2 Java Yes
application/x-java-applet;version=1.3 Java Yes
application/x-java-applet;version=1.3.1 Java Yes
application/x-java-applet;version=1.4 Java Yes
application/x-java-applet;version=1.4.1 Java Yes
application/x-java-applet;version=1.4.2 Java Yes
application/x-java-applet;version=1.5 Java Yes
application/x-java-applet;version=1.6 Java Yes
application/x-java-applet;jpi-version=1.6 Java Yes
application/x-java-bean Java Yes
application/x-java-bean;version=1.1 Java Yes
application/x-java-bean;version=1.1.1 Java Yes
application/x-java-bean;version=1.1.2 Java Yes
application/x-java-bean;version=1.1.3 Java Yes
application/x-java-bean;version=1.2 Java Yes
application/x-java-bean;version=1.2.1 Java Yes
application/x-java-bean;version=1.2.2 Java Yes
application/x-java-bean;version=1.3 Java Yes
application/x-java-bean;version=1.3.1 Java Yes
application/x-java-bean;version=1.4 Java Yes
application/x-java-bean;version=1.4.1 Java Yes
application/x-java-bean;version=1.4.2 Java Yes
application/x-java-bean;version=1.5 Java Yes
application/x-java-bean;version=1.6 Java Yes
application/x-java-bean;jpi-version=1.6 Java Yes

Unless you have installed Mozilla/Firefox from their own installer (I don't think you have, you call it Ice Weasel) the directions you find on plugindoc might not apply in your case. Debian repackages Ice Weasel and some file locations/folder names may be different. I have been through a couple of rounds of musicalfolders as my debian install is old old and went from mozilla>Firefox>Iceweasel>Ice Ape Your problem could be something is in the wrong location?

Perhaps try to get your java fix proper for your debian.

apt-get install sun-java6-jdk

Although you say etch, maybe 6 isn't in the stable repo yet, so try apt-get install sun-java5-jdk

I've installed v1.5.0.11 of the jre using the exact same procedure I used with 1.6.0, and it works perfectly.