Try this ... set up a new account on your computer & install LW into it. If LW works then you know the problem is with your main account. BTW accounts are easily created & deleted. Use the Accounts section of your system prefs to create a new account.
I think now with OS 10.4.7 Java 1.5 is the default. It might also be worth as an experiment swapping it over to Java 1.4.2 for LW to see if you have the same problems. You can do this using using the Java utility
Setting up Java 1.5.
Invalid memory access of location 00000000 eip=9ba40767
Bus error
An unexpected Java error has been detected by HotSpot Virtual Machine:
Java VM: Java HotSpot(TM) Client VM (1.5.0_06-64 mixed mode, sharing)
Bus Error (0xa) at pc=0x9ba40767, pid=496, tid=25169920
I saw a lot of thread_blocked recordings. The impression I get is the resources are maximising attempting to overcome this issue but ends up failing. Something is failing with the Java. Though I'm not sure why Bus error is implied. Unless it's an illegal bus location. Or that's simply where the data loading is failing. I'll need to get some advice from others about this.