QTR-Quadtone RIP

I have just purchased the QTR and installed in my PC (XP Prof). Also 
have flushed my Epson 7000 and replaced inks with a set of K6. What I 
am now finding is that the prints I was making with an older BW Pro RIP 
do not print even vaguely close to how they used to print. Am I needing 
to start all over again - did I miss something. My nozzle check is 
perfect albeit two of them are quyite faint but I am told this is 
normal. Any suggestion/cures out there..Many thanks