Marco,
I would sugest you to try this:
1 - Make sure your nvidia's (from nvidia.com) GLX drivers are working.
2 - Clean your ~/.cxoffice directory to start a new installation with a clean system.
3 - Besides copying the files from a Windows partition, try to mount your CDROM this way:
mount /dev/cdrom /mnt/cdrom -t iso9660 -o ro,unhide
Make sure that /dev/cdrom and /mnt/cdrom are correct with your system.
The unhide option passed is used with CDs with copy-protection, I thinks that's why you see only 45MB.
4 - After mounting, try to install de game.
5 - After install, I'd suggest you to go to www.gamecopyworld.com and get a NO-CD patch for your WC3, it will help you a lot.
This way the english version is working great here, please let me know if it worked for you.
[]'s
Renato