Looks ok when seting up in toolbag,

but as soon as I preview it in the viewer I get these white lines,

So I've deleted the maps and brought them in one by one and previewing each time, it's when I bring in the normal map that it happens. Yet I've followed the guidelines from this very forum (where it's worked fine for me in the past) but this time it's not happy at all. Any ideas? Here are my settings for the normal map.
