Cannot make custom item icons

[KiraImmortal]

problem again :/ i used photoshop to erase the background and the Paint.Net to convert the image file into .tga. my first attempt was succesful! i overwrote the original laudanum image, and it's working. i made 3 more files, but there are white noises or whatever on them when i move the cursor over.. except the first one, all other attempts were failed, and i used the same erasing and converting method.. is there a solution for this? http://i.tinyuploads.com/Nh2qP0.jpg