Sharing Excel files with linked cells on network

I’m using an imac with leopard version 6. In my Public Folder, I have several Excel workbooks, that have cells linked from workbook to workbook. Any single workbook will open without problem on the host computer, but when it is opened on another computer on the network, Excel cannot find the workbooks to which the opened workbook is linked. If I edit and reset the links from the network computer, it will update the links, but then the workbook will no longer update when it is reopened on the host computer. Is this a path:name problem, an Excel problem, or a network problem?