They are used the same way as the others were. You should be able to teleport to the Grand Knight waypoint or the one just outside of the battle tower.
This can be a copy protection issue.
Are you using an illegal version / noCD fix version of the game?
Is your DVD in the primary DVD drive? (lowest drive letter, such as D:) There are reports of SecuRom messing up on people that have multiple CD/DVD drives on their computers.
It can be a bad DVD.
Anyway, you might have to load to a previously saved game to get them to work properly again.
