How can i fix that, on the old version(0.7.x) isnt that much

EDIT: I was playing w3 and left the window of jdownload opened then when i stop playing(one half hour after) my computer was verryy slow so i open the task manager and saw java.exe using 580mb so i force finished it(i cant close it normal way, much slow) and opened again and know is runing javaw.exe using 60mb, but i checked it again and its growing the memory and know its on 107mb(holy shit)

how can i fix that omg