volume indocator missing? 4.3 xperia V

[beermejo]

Hi all, first post, just to ask if anyone had this problem, it turns that after doing the last 4.3 update in xperia v made the volume indicator (the slide level that appears when you press the volume buttons) disappeared, turning in a black square as shown im the image, next to the clock
subir fotos
Has anyone had this problem and solved it please?? Thank you so much in advance