I just tried it and if working you get a chat window. I just got a 'Host is unavailable' reply. I believe it means that the person you are requesting 'chat' with has either quit Limewire, or has logged off the internet and the 'Host is unavailable'. Also they may just not reply. I have only had one person reply to my requests to 'chat' in the several years that I have been using LW.
I think you are doing everything right.