Well, when you open up bank, you can see on the bottom left
corner 2 little buttons. "Bank entire inventory" and "Unequip worn items"
When you press "Unequip worn items" then your items go to your inventory.
So I was wearing some quite expensive things and clicked fast on "unequip worn items"
and "bank entire inventory"
Maybe it was too fast and my items didn't appear in bank.
lost my dragon boots, dragon scimitar, dragon fire shield, helf of neitiznot, amulet of glory, mithril arrows and dragon gloves