Problems with AutoCAD Plans on PDF - Problems reg. appearance on scaled papersizes

Hi,

i have the problem that a printed plan on pdf (e.g. ISO A1) looks correct reg. lineweights on the PC and also when its plotted in the original size (A1). BUT when I print the same sheet on A3 (fit to papersize) from Acrobat, everything looks way too thin. the hatches even show up just partially (ANSI 37).

The funniest thing is that other plans with the exact same settings in autocad dont have that problem.

I think its no autocad problem, but a pdf problem?

Does anybody have experienced such a problem or see an obvious solution?

Is the problem-plan maybe too "heavy" - too much information? when i am deleting the hatches completely, the same plan looks right concerning lineweights when fitted to a smaller papersize... so are the hatches the BIG problem?

Since it is an urgent problem in a big project, i would be very happy if anybody could help me...

greets ron