OH, i thought i included it it my reply about the scale, the black lines is definitely an issue with the scalesize, i noticed on mine when i increased the scale to even 1.01 i got the black lines, however not as bad as above, maybe one vertical break every 30 tiles or so. it should be easy to reproduce with that knowledge.
as with Dan i can only confirm this happens under windows, i kicked out the idea before i attempted an android build so i cant say if it is a windows only problem or all platforms.
Dan: if your still trying to figure it out, everything returns at 1 because the director itself is scaled, and i do believe that scale comes last, kinda like looking at the screen with a magnifying(or the opposite in your case) glass. I'm not sure if that helps but i really not sure how to explain it better.
its an issue with the scaling, not so much the map renderer not correctly resizing the tiles, otherwise my 1.01 scale would have had the opposite effect, overlaying tiles as opposed to black lines.
I had problems with that default scaling since the start with the old tilemap engine, i found the only fix i had was restrict it to 1 resolution show full size, and adjust on screen elements for possible clipping detection should the need arise(and it does, i dont know why phones dont all have a standard set of resolutions like TV's do).