Quite a lot of information missing to make an informed comment. What are your Job Properties settings, colour profile setup, pdf profile, etc. What type of images are they - jpeg, tiff, RGB, CMYK. Throw us a bone and I'll get my dog to fetch it! ;-)
Konica Minolta bizhubpress C1085 - Fiery System FS150 Pro
Fiery IC-308 v2.0 - CWS 5.8.0.39 SP2 on Windows 7 Pro SP1
Konica Minolta bizhub Pro C6501 (65C-KM V 3.0) - Fiery System 9
Xerox DC250 (DC250 V 1.2) - Fiery System 8e Release 2
Fiery Pro80 65-55C-KM PS Color Server 3.0a eu - CWS 5 (5.7.0.29) on Windows XP SP2
EFI CWS 6.1 (6.1.0.28) on Dell Studio XPS running Windows 7 Pro
AMD Athlon II X4 640 3.00GHz 4Gb RAM