Thanks Tim. Will study (when time) but I'm not an expert on DX regretably.
MGE Dev: http://www.greyaliengames.com/framework.php scroll down and get "make me happy". Depending on the type of tile the issue is worse. It only happens at floating point coords of course because the edge is anti-aliased. If it was drawn at integer coords to a giant texture of many tiles and then the big texture was drawn at floating point coords, you wouldn't get the issue.
MGE Dev: http://www.greyaliengames.com/framework.php scroll down and get "make me happy". Depending on the type of tile the issue is worse. It only happens at floating point coords of course because the edge is anti-aliased. If it was drawn at integer coords to a giant texture of many tiles and then the big texture was drawn at floating point coords, you wouldn't get the issue.