You might have stumbled across a few bugs there. Did you find the hair in the barber shop after it was cut by Stan or without solving that puzzle?
As this game uses a pretty old engine there are some problems that occur when you play it with only limited memory. AFAIK this causes some screens to stay black and sometimes only display animations. I honestly don't know what might cause the invisible fish bowl in the inventory.
Unfortunately I could never reproduce these problems for me so I have no way to tell what is really causing this.