All three Lua tutorials have now been updated to cover version 5.1 of Lua. I've also started working on a fourth Lua tutorial that's more of a real world example of using scripts within a game. Hopefully I'll have it finished next week.
The downloads have been updated to include project files for Visual C++ 2005. I can't think of any good reason to support Visual C++ 6 anymore. I left the older downloads at the bottom of each tutorial in case anyone is still interested in Lua 4.0 or 5.0.