floor tiles are wonky

i'm trying to create floor tiles, but some of them act weird. instead of one tile showing the full 512x512 image i set for ONE TILE, it acts like a bunch of tiles need to make the full image. so when i move the tile around before setting it, it shows different parts of the image as if it's huge. it's not, i checked, and every swatch is 512x512 just like the original floor. four of the swatches work fine. what is happening?