Digital BW, The Print

Bizarre, bizarre...

I printed a grey tiff through QTRgui (Windows, PS CS) for the firt 
time on an Epson 4000: 100% neutral (EAM, blend with cool and cool-
s), I was very happy.

A couple of days later, I tried to print an other grey tiff with QTR 
(same settings): what an horrible green cast! 

I've tried many times (including the first picture I printed first) 
with the same settings, same blend, same paper, etc... still this 
cast; looks like as if the Epson driver was buypassing the QTR RIP.

Any clue?

I was so happy with my first print!

Thank you very much for your advise, I really need to understand 
what's happened.

Is is possible that the settings in PS concerning the softproofing 
and the colour settings (workspace) which I've modified since for 
colour printing, could interfer with QTR? What settings do you use 
for the colour management/printing options when using QTR?

JM Humbert
Paris, France