You are the second person to post about problems with Lion. Unfortunately I do not have Lion. And your problem reported is different to the other. Could possibly try my suggestion in this thread http://www.gnutellaforums.com/genera...c-os-lion.html perhaps it might help.

If you upgraded to Lion from a previous OSX, perhaps it might be worth deleting the LW preferences folder (but backing up your downloads.dat file) Deleting LW Preferences folder in OSX. This will also mean you will lose settings such as shared & such. If you wish to back up the shared files, also back up both Library files found in the preferences folder. Let us know if this has any effect on your problem.
Umm .. as far as I know, LW 5.5.16 no longer works. Do not attempt to use any LW version after 5.5.10 with exception of 5.6 beta or LimeWire Pirate Edition (LPE 5.6.2.) See http://www.gnutellaforums.com/mac-os...link-here.html for older versions. LPE is listed. I suspect this might be your problem.

If using a non LPE version, you will most likely need to run the ConnectFix program. The error you received is rather typical if unable to connect. It took me several minutes to realise.

BTW if the OSX firewall is off you will probably not see options to make exceptions for various programs. If the firewall is on, the option will probably be to click on advanced, then you will see the options to add or block programs.

There were no improvements to LW after 5.5.10, the updates were in relation to the program update facility & limeshop only. ie: the LW dev team were being dictated to to get an auto-update function working to force the program to stop working.

I've no immediate plans to upgrade to OSX 10.7 Lion. Without Rosetta support I'd lose ability to use lots of important programs. Apple has no plans to bring Rosetta back. And I've read where several other applications are buggy when run in Lion presently.