In the geogebra packages included in Natty and older versions of Ubuntu, icedtea-plugin is listed as a recommended package (see http://packages.ubuntu.com/natty/geogebra ). In Oneiric, it is now a dependency (see http://packages.ubuntu.com/oneiric/geogebra ).
This is a problem as the icedtea-plugin is known to be unable to run many applets created with GeoGebra, for example all those on this page: http://dmentrard.free.fr/GEOGEBRA/Sciences/accueilscie.htm (click for example on the first one called "Ondes sismiques"). For this reason, it was a common practice to replace the icedtea-plugin by Sun Java.
Now this is no more possible, as uninstalling icedtea-plugin also uninstalls geogebra itself!
I would expect the geogebra package in Oneiric not to include icedtea-plugin as a dependency.
I forgot to mention that the icedtea-plugin was renamed in Oneiric, which may be the reason for the problem:
- in Maverick and Natty, it was called icedtea6-plugin
- in Oneiric, it is now called icedtea-plugin (without the "6")
But it is indeed the same software,still having the same problem to run applets created with GeoGebra.