Dashed line, eh? Hmmm...how far apart are the dashes? Specifically, are they spaced apart by a greater distance than the standard raster lines?
(I posted a reply to your other post about the vertical line problem). In any case, I put together a doc that covers this and other problems (and their fixes). Our gracious host with the most has archived it somewhere on this site, but I have no idea how one accesses it. Perhaps he will be forthcoming with some instructions. Version 1 is over at Gamba's site; Version 2 has pics, and the material has been rearranged a bit for clarity.