It could be an account specific issue. Try setting up a test account & see if same issue; 
Setting up a Test Account in OSX (click on link). 
If same issue, might I suggest you try installing LW 4.16. 
http://www.gnutellaforums.com/mac-os...tml#post271009. 
Also try changing your Java version priority around:  
Setting up Java 1.5; drag the first preference to the top of the list. 
 
 
If you have not done it recently, I'd recommend a Safe Boot & Repair permissions:   
SAFE Boot & Repair Permissions