Are you seeing a Wall over the Blue Globe ?? Which indicates a Firewall. May be in your Router. Please supply the following Information, in paticular the Make and Model # of your Router. It could even be your ISP Throttling your connection.
System details - help us to help you -> Provide these details when you post!!!
Also Noticed you Upgraded LW. Sometimes Deleting the Pref Folder will Fix this Problem. For some reason the Prefs get corrupted after an upgrade. If you try this, write down your settings as this will delete them and you'll have to go back and set them up again.