Xml thumbnail gallery - images carrying over?

Hey guys! So I’ve got three different thumbnail picture galleries referencing three seperate xml documents. So lets say there’s 5 thumbnails in gallery A and 2 thumbnails in gallery B…for some reason when I switch from A to B the three remaining images from gallery A carry over into the wrong gallery. I hope I made my situation clearer rather than confusing with my example, but does anyone know why this might be happening? Thank you in advance!