How do I make sure my tiled background renders correctly

I'm trying to insert a tiled background (I'm using a 512*64 image, which I believe should be fine), but for some reason I get this thin white line on the top border of it.

There is no line like this in Gimp, so it's kind of confusing. Has anyone encountered something similar?

It looks like this:

[attachment=0:20yl7aty][/attachment:20yl7aty]

try to save the picture with paint.net or an other program. i think this isn't a construct bug

Sampling to "Point" , not to "Linear" if you want to have no glitch.

Thanks, I might need to switch to Point, even if I was hoping for a more "HD" experience

Ah, I found out what the problem was, if anyone for some reason wondered about something similar. User error, of course. Basically I had filled up the image all the way down to the bottom, so this somehow wrapped to the top, in lack of a better way of explaining it.