There have been alot of people with the same issue...
It sounds like fake Ultrapeers, which in return will leed you to fake files and such....
This has helped a few...
Try going to your Connections Tab in limewire, if it's not showing up go to Veiw > Show/Hide and make sure the connection tab has a tick next to it...
Then click on the Hosts and remove them and let Limewire search for some more...
(try to take note of the hosts IP numbers if the same ones keep re-appearing add them to your host filter...)
Tools > Options > Filters and select the Host Filter and add these IP's into it and select apply...
Another thing if you are using limewire 4.13 and later you can apply this hostile list...
The TechNutopia Fullsize Hostiles List for BearShare and LimeWire
Also do you use PeerGuardian at all....
If not install it and turn it on before you start limewire up...
Peerguardian __(FREE)