Well, first I have to say my German keyboard (like all German keyboards) has no "Right Alt" key as such - so I tried AltGr+Enter instead. The game (which had been running very well in its window before I did that) freezed immediately without going full-screen.
My system is a Core2Quad running at 2.83 GHz with 4 gigs of RAM, Asus P5B mainboard, and a GTX 260 GPU.
My OS is Ubuntu Linux 12.10 (Quantal) amd64 Beta 2, fully updated to newest packages just an hour ago.
uname -a gives: Linux tearex 3.5.0-17-generic #28-Ubuntu SMP Tue Oct 9 19:31:23 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
java -version gives: java version "1.7.0_07" OpenJDK Runtime Environment (IcedTea7 2.3.2) (7u7-2.3.2a-1ubuntu1) OpenJDK 64-Bit Server VM (build 23.2-b09, mixed mode).
firefox -version gives: Mozilla Firefox 16.0.1, and the about: page says Build identifier: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:16.0) Gecko/20100101 Firefox/16.0.
Thanks for your great effort at this!
EDIT: My computer has no speakers connected at this moment, so I can't say if sound worked or not.