Are they missing or Hidden?

Hans Näslund wrote:
> The last few weeks, I am have lost two important icons in the taskbar's
> notification area - the "Safely remove hardware" icon and the "Sounds and
> Audio Devices" icon. I can restore them, but each I restart the computer
> they are missing again.
>
> I have been searching for an explanation or a solution, but so far in
> vain.
>
> Does anybody have a hint?