I have a master workbook set up and wanted to create a link to several
individual workbooks.

So I copied the appropriate worksheet from the master workbook and went to
the new workbook and did:
1. Paste Special: Paste Link
2. Paste Special: Column Width
3. Paste Special: Formats

In the master spreadsheet I had conditional formatting set which pasted into
the linked worksheet fine. I tested this with conditional formatting that
made cells yellow when due and red when late and it worked. Again I tested
this and it worked fine. I added one more condition which was if the cell
with client initials was blank then format date cells with no background
fill. This seems to have been a problem because now the whole linking thing
isn't working.

Does that make any sense?

Hopefully that is enough information.