Why is the C: the slave? it should be the Primary Master.
The DVD drive should be on a separate cable and be the Secondary Master.
See this http://www.buildyourown.org.uk/pc-articles/ide-configuration/ for how it should be. Note that the Master goes on the middle connector.
Don't forget to check the jumper on the back of the Harddrive there will be a diagram of which pins to put the jumper on. (diagram is on the label of the Harddrive)