Can you verify that Java 1.4 is the only problem you have? See if it is Java 1.4 causing the problem. I ran TWS with Java 1.4 and thought it ran slow so I went with the older Java verson.
I had similar experience with JAVA 1.4 v.s. 1.3.1 until I deselected the Console (check: "Do Not Start The JAVA Console"). That seemed to fix it.