Problems on running Idea under Linux

Hi, I'm trying to use Idea under Fedora 11. I get the follwing messages if I try to run the idea.sh

[caterpillar@Portatile bin]$ sh inspect.sh
Exception in thread "main" java.lang.NoClassDefFoundError: com/intellij/idea/Main
Caused by: java.lang.ClassNotFoundException: com.intellij.idea.Main
        at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:323)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:268)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:336)
Could not find the main class: com.intellij.idea.Main. Program will exit.


How can I do to make run IDEA?