When clicking Print > Adobe PDF the filesize is nice and small but the legend gets messed up.
Does anyone know how to fix this?
I am aware of the Export > PDF and of the reduce DPI and Re-sampling sizes.
If you're using Print ->Adobe PDF then what you're actually doing is using a print-driver to create the PDF. The problem therefore is with whatever PDF print driver you're using.
Try using a different one there are some comparisons here:
Myself I use the free and Open Source PDFCreator with no problems.