problems with Konica 7130 printing

[Rob]

We have been experiencing unpleasant problems with Konica 7130 printing since we went to AC 8.x platform. Some of the fills printed from AC (sometimes from Plotmaker as well) are converted to pure black (sometimes even with white-colour pen settings). It works on sort of "random" basis and drawings can get printed differently on different storeys (the very same pen colour and type of fill). We thought that it could be a printer driver but it works flawlessly with AC 7 . Is there a different internal definition of fills with AC8.x ? Has anybody experienced similar problem? It doesn’t seem to be a problem of All colours to Black settings in the printer dialog box and/or Display Options/Polygon Fills settings...