In order to help you further, we really need to know about your system...

What computer
What Operating System
Type of internet connection
How you are connected to the internet (as in what 'boxes' are between your machine and the telephone line)
What other programs you may have running at the same time as LimeWire

Also, is your LimeWire v 3.8.7 a 'new' and 'first-time ever' install, or have you re-installed it or made an upgrade from an earlier version ?

The more you tell in the first post(s), the faster you may find the 'solution' !

Last question for now... When you click on the Connections tab in LimeWire, what do you see ?