Since this 3 year old thread has been "revived" and also, since I just downloaded LimeWire 4.18.3 and experienced the same problem when attempting a search

"LimeWire is currently connecting..."

I fixed this by taking these following steps:

1. disconnect LimeWire (even though it's not fully connected anyway)

2. Navigate to menu Tools -> Options -> Speed

3. REMOVE check mark from "Enable OOB Searching:"

4. reconnect and Bob's your uncle

seems some internet connections do not work well with this feature, this fixed the problem for me. hope it helps anyone else.