I presume that means you're using OSX right? LW runs on Java. Java for mac is far from perfect & apparently results in some memory leakage. It also can take up some virtual memory space/scratch disk (ie:hdd space.) All I could suggest would be to keep your java updated. And if you're using high-end apps to try to just run one at a time. Either that or just run LW in spells. After each time the vm & real memory use that accumulates will be wiped. I think et voilą would be best at answering this, but anyway.
To get an idea of what I'm refering to see:
http://www.gnutellaforums.com/showth...5968#post95968