You should not disable your firewall ... configure it so it allows LW full access. But only keep one firewall active;
Firewall configuration instructions (click on link), or for Norton see
Configuring Norton Internet Security
Do you see a brick wall in front of the blue world icon at the bottom of LW's interface? (see sample image attachment below)
If you want to increase opportunities of sharing, enable Partial File Sharing in your Sharing options.
Go to LW's Library window, select one of your shared folders & look to the columns to the right. Look under Hits & Uploads columns. Hits shows those files have been found in other peoples searches for whatever reason. Uploads shows uploads be they partial or full.