You can take some suggestions from Kappy in this thread.  You can find out if Java is running properly by going here:

booka on this thread says “this page: http://www.java.com/en/download/help/testvm.xml

shows me that java is not available or not installed…”

You might also need to update to the newest version of Java.  Check Software Updates to see if a new Java machine is available and install it.