I installed Warcraft III: RoC and TFT with the downloaded installers from the Blizzard online store.
I started up WC 3: TFT running under Crossover Games version 7.1 for Mac OS X and came up with the following error.
http://img401.imageshack.us/img401/3807/picture1wf0.png
I had to quit (not force quit) CX games to exit WC, but I repeated the startup and again the same error came up.
After this I tried the suggestion in 'Thread: Won't start up', that is removing the Movies folder, and voila!
http://img291.imageshack.us/img291/7315/picture3fs6.png
The game starts and runs perfectly, the only problems that I can find at the moment are that it only seems to support up to 1024x768x32 resolution, which does not allow for widescreen, and that Battle.net does not seem to be able to connect.
It does not require the CD to run as the downloaded installer includes the required files to run the game (the .mpq files that have to be copied with version 1.21b).
I hope this has helped someone and if anyone can work out how to get Battle.net to work, I would be very appreciative.