Even more interesting: I removed Lua and Luabind, so I could package up the project and post it here, and now the connection magically works...
Ouch. Are you sure you have made a full recompile of the project? If you insert those libraries again, is the problem reproduced? Can you ping directly via your O/S to the address you are trying to connect to?
Contrary to what the previous poster says, there's nothing wrong with having a zero as the third octet in an IPv4 address. For instance, this is the default on some Netgear routers.
They also do not have to (but usually do in typical setups) reside on the first IP in the range. There's nothing non-standard about this and it likely has nothing to do with your problem.