I have noticed references to a lame server in my log. What is a lame server and do I need to be worried about it?

You don't need to worry about it.
Basically it's somebody else's server which has a problem with its DNS configuration.
For example, a mailing list's server could be domain.com , if for some reason the main DNS was changed on the server, but not in the registrar's database it would cause this error...