Can you explain your situation a bit further, if possible? Does the items not show up at all? In the designated list, do the item's titles appear or no? Are all the items doing this or merely a selective few? My apologies for the questions, but answering them will help me achieve a better grasp.
As for the person whom sees the items differently, it's quite possible that they have a different items pack or different item.cfg list which results in users bearing witness to different items on those whose list do not match entirely. Are you sure you have the same item pack?