Thanks for your reply, the file does have macros, hence the .xlsm extention, they started as excel 2003 .xls files but have been updated to excel 2007.
I have tried just making a couple of very simple .xlsm files and linking those, and they seemed to work, I also linked one of these simple files with the template that I am having trouble with and that worked.
But as soon as I try and link the more complex files excel just crashes each time unless I have both files open and just copy and "paste special" links. What I do is have a weekly file with loads of info that is linked to the previous week to get four and ten week trends and then link the weekly reports to a monthly summary. Been doing this for about twelve years with no dramas.
Normally I was just using a find and replace search which was really quick and easy.