Skeetendo

Hi guys! this is my first time being here, my name is Azara, nice to meet you guys :)
This my first topic, I got a problem when inserting 257 sprites with Agixp, I make the correct size sprites of the pokemons but when I insert them all. some sprites become uncorrect size and get crash, when i ireplace the sprites  to the crash sprites, they will many sprites crash too :(
what happen? can anyone help me? and sorry if my english really bad :(