Rasterquality reduced about 50 % when Rasterized is active

When plotting with PW-Interplot (08.09.04.84) and set  the Rasterized Option active, the resolution of the Rasterreference will be plotted at a reduced Quality of about 50 %. Is the Rasterized Option deactivated, the output is fine (Quality Factor=50). To increase the Quality to get the same Resolution when plotting "rasterized"  we need to change the Quality Factor to 100.