RubyMine для Linux

Я новичок в Ubuntu, и у меня возникла проблема. Я не могу запустить RubyMine 4:

kvet@Kvet-Notebook:~/RubyMine-4.0.3/bin$ java -version
java version "1.7.0_03"
OpenJDK Runtime Environment (IcedTea7 2.1.1pre) (7~u3-2.1.1~pre1-1ubuntu2)
OpenJDK 64-Bit Server VM (build 22.0-b10, mixed mode)
kvet@Kvet-Notebook:~/RubyMine-4.0.3/bin$./rubymine.sh
OpenJDK Runtime Environment (IcedTea7 2.1.1pre) (7~u3-2.1.1~pre1-1ubuntu2)
OpenJDK 64-Bit Server VM (build 22.0-b10, mixed mode)
OpenJDK 64-Bit Server VM (build 22.0-b10, mixed mode)
WARNING: You are launching the IDE using OpenJDK Java runtime.

         THIS IS STRICTLY UNSUPPORTED DUE TO KNOWN PERFORMANCE AND GRAPHICS PROBLEMS!

NOTE:    If you have both Oracle (Sun) JDK and OpenJDK installed
         please validate either RUBYMINE_JDK, JDK_HOME, or JAVA_HOME environment variable points to valid Oracle (Sun) JDK installation.
         See http://ow.ly/6TuKQ for more info on switching default JDK.

Press Enter to continue.

Error: Could not find or load main class com.intellij.idea.Main

Я попытался установить openjdk6 и получил ту же ошибку. Я не знаю, что я должен делать.