I used to use Microsoft Office LiveMeeting Web client without problems in Karmic and before that. In Karmic I was using sun-java5-plugin but that is no longer available in Lucid, so now I use sun-java6-plugin.
Luckily they have a test page... Browsing to https://www125.livemeeting.com/cc/test2007/webJoin?id=LiveMeeting2007Test&pw=&role=attend&cn=user and clicking "Join Meeting", (then if needed, allow popups for that page and click Join Meeting again) a window comes up to host the applet and has a bunch of Loading... messages. Then they all go away, and a separate Java Applet Window comes up with almost no size, centered in the middle of the screen. And then nothing happens.
In one of my tests firefox hung at that point, but usually firefox is still responsive but the applet does nothing.
Again, this all worked fine in Karmic with sun-java5-jre. When it works, from the URL above you wind up looking at a remote powerpoint slide that says it worked.
$ apt-cache policy sun-java6-plugin
sun-java6-plugin:
Installed: 6.20dlj-1ubuntu3
Candidate: 6.20dlj-1ubuntu3
Version table:
*** 6.20dlj-1ubuntu3 0
500 http://archive.canonical.com/ubuntu/ lucid/partner Packages
100 /var/lib/dpkg/status
Booted my Karmic install to confirm that it still works. It does, but I misremembered the java version in that install... it's actually 6-06.
sun-java6-plugin:
Installed: 6-06-0ubuntu1
Candidate: 6-06-0ubuntu1
Version table:
*** 6-06-0ubuntu1 0
100 /var/lib/