Which version of Java did you install? When you install LW it only requests to dwnld the minimum version of 1.3 but it's better, much better for LW to use a later version:
Java 1.4.2 (click on link)
What I can think of are 3 things to try:
Go to LW's menu Tools>Options>Advanced>System Startup & untick Run on Startup. Press the Apply button.
Do you run as an Ultrapeer? If you do unintentionally you can disable it. Go to Tools>Options>Speed & tick the Disabel Ultrapeer option box.
Go to Tools>Options>Shutdown & select the Shutdown immediately option box. Again, make sure you press the Apply button.