Printable View
Draw a dotted line, set it to overprint with a pantone solid color (can be any color)
now
Draw a straight line, set it to overprint with a pantone solid color as above.
export as pdf/-x
open in acrobat pro, then check overprint and you will see that dotted line will not overprint.
Can I ask 2 questions here, since you are using spot colour. I take in Acro you kept these as spot colours in the separations dialogue. Did you run a Pre-flight check on PDF x/1? I did what you asked and can see overprinting where the lines cross so I cant replicate that at the moment however I did rush it! The line colour shows colour change when I selected "output preview", deselect process colours as it is for spot colours, then select "preview Colour warnings" and the check the "Show overprinting" in the warnings field.
okay here is a sample pdf/-x1
open it in acrobat pro, set it to show simulate overprinting
you can see that the dotted line is not overprint, even though it was set to overprint in xara.
Yes I agree that it is a bug in the PDF export as all you need to do is to bring the file into Illy and give it on Overprint Line in the Attributes panel and re-save it and then it works. There are a few other problems here as it depends on the stroke type that you select whither the export does it as a line or an object. In a recent newsletter I did I used broken lines which werevery thick as separator on a heading and did not have any problems after doing a preflight and it printed well. Tend not to use Acro but Illy to soft proof PDF files made in XPro. Maybe worth while to make out a ticket at http://support.xara.com/
Thanks
Apparently the line should be converted to shape first.