Just a side-comment, AFAIK the Westell & 2Wire are not the most reliable devices. Do you see a brick wall in front of the blue world icon at the bottom of LW's interface?

For Tiger, make sure you're using Java 1.5; ie: Setting up Java 1.5

This may help: Tip: Purge the Downloads Queue!

For OSX, it's best not to share more than about 2,000 files. I sometimes share more but it does eat up the VM & RAM because mac's java is not especially efficient. Too many incomplete files has the same or even much worse effect!

When you open LW, let it settle before using. You might want to disable Ultrapeer mode (found under Speed settings.) Also reducing both upload & downld bandwidth slightly might also help.