i was having the same problem many have had...globe behind the brick wall, deleted mcafee firewall/spyware/etc, turned off windows firewall, added port forwarding, etc.....
the way i fixed my computer:
1. turned windows firewall off
2. went to exceptions in firewall list & deleted the limewire ports & the version of limewire listed (4.12)
3. added limewire back to exceptions list & it came up as version 4.16
4. turned windows firewall back on & limewire connected no problem

hope this helps some folks