If you have more than one dvd-drive it could be that Tages works only with the lowest in alphabetical order.

I only have one DVD drive in my machine.

I checked out Nero's webstie for any tools to slow down my drive but I couldn't seem to find anything.

I'm starting to think my drive is incompatible… I have this same problem with Gothic 2 now that I think of it… ended up buying G2 from GoG to resolve that problem.

I've now noticed on my windows XP machine that I get the 'Please Insert Original DVD "Risen"' error message. However, on that machine, if I quickly double-click the risen icon a SECOND time after getting the error message the game will start. Unfortunatley, this doesn't work on my Vista rig.