I forgot to mention that I run my main character from a seperate WOW folder (Different from the one that I solo play with) and then I have the other 4 slaves using the same WOW folder (But seperate in themselves from the main chars WOW folder I use for boxing).

I guess my other option would be maybe to put the slaves folders on my other HD? I heard that improved performance and the only other thing I can think of would be to make a seperate folder for each slave as well on the other HD?