I have an Ibook G4, runs OS 10.4.11, and the ONLY solution I have found, after all the proposed solutions here to a 'failure to connect' problem is to run an old Limewire version using Mac Classic. I am currently using Limewire 4.0.10 with OS version 9.2, and it connects quickly, searches quickly and downloads quickly. later versions don't connect at all.

I find the gnutella.net file seems to go stale fairly quickly with LW 4.16.6. I do also run LW 5 in a different account, so I swap the gnutella.net file across (whilst LW is closed) & it connects again.

Glad to hear you at least found a solution of sorts, similar to my occasional one actually. But not really a totally happy permanent solution. Likewise, last several times I tried, my OS 9 LW connected well.

LW developers recognised the connection issue with LW and put in a function of a kind of self seeking for fresh active ultrapeers. Unfortunately they only discovered this issue after LW 5 was released & refuse to update the issue for LW 4.

Edit: you may wish to consider copying your OS 9 LW gnutella.net to your other OSX LW preferences folder & replacing the OSX one.