how can stick the piclayer to map layer correctly?

[3pd.ala]

Do you know why my background(piclayer,raster map,JPEG or PNG format)in JOSM has problem?
Piclayer is not stick to map layer correctly , and not move fine.when I move them with right click,both of them moved but pic layer moving is slower than map layer.

--both layers move when drag them ,but piclayer so slower than top layer.means when drag both layers to left, background moved to left too,but with a little diffrence
piclayer is lazy!!!--