Hi, thanks for the reply. I don't know, I immediately got the same error when I went back to: for i:= DXSpriteEngine.Engine.AllCount-1 downto 0 do ...... Delphi stops at Sprite.Dead, FEngine.FDeadList.Add(Self);

And when I call spriteEngine.dead immediately after calling bullet.dead in my collission procedure I get an error about Index being out of bounds...

I did put .dead before .move as you suggested and changed back to engine.clear and no errors.

Do you maybe know when UnDelphiX will be made bug free? I know I should be learing other libraries like SDL and OpenGl, but I like UnDelphiX and it will allways have a soft spot for me because I started game programming with it :-)