How long did you wait until you gave up on limewire and quit the program?

Especially after not using limewire for a while, it may take limewire some time to find good hosts to connect to. As long as limewire has not established a firm connection with at least one other host, you will see the red dot and it will say 'disconnected' in the title bar.

In order to check whether limewire actually is in fact searching for good hosts, check the 'connections' tab. If it says 'connecting' or 'handshaking', you should eventually connect. If there's nothing, then there's either some other kind of problem or you unchecked the 'connect on startup' checkbox in the options.

hope that helps, good luck!