I've got fixes for both the Calibration Mode and the Color JPG issues.
Before issuing a new release I have these fixes as a patch:
http://www.quadtonerip.com/QTR2.7.0patch.zip
Download this zip file, extract both imagetoraster.exe and quadtoprinter.exe
Put both these files into:
\\Program Files\QuadToneRIP\bin
replacing the existing ones.
RoyMessage
Fixes for QTR 2.7.0 on PC Windows
2010-04-07 by Roy