GIMP :: How To Put Symbol On Back Of A Piece Of Armor

I'm modding a game at present and wanted to put a symbol on the back of a piece of armor.

I created the armor and symbol in seperate files, then opened the armor file, then did an "open as new layer" for the symbol I wish to paint on the back of the armor.

I'm obviously having some kind of context issue, every time I click the image to move it around the "Adjust Color Balance" menu pops up instead of allowing me to move the symbol around.