Are you on a wireless LAN?
Wireless routers often cannot handle the number of connections KL++ can create per second. This is especially true the further away your computer is from the wireless router.
Are you using a router?
If so, are you port-forwarding the ip port KL++ wants to use?
Also, are you trying to use KaNAT?
Without port-forwarding AND KaNAT, your connection is firewalled and very hard to connect to. It eliminates your ability to download from firewalled Kazaa/KL++ users.
Is your LAN in the 192.168.x.x address space?
(If so, do you see a LOT of connections TO 192.168.x.x while running KL++?)
This is the Kazaa/KL++ 'DDoS attack' bug in action, and it can no doubt knock out connections.