Excel update links keeps freezing

This is weird but here goes. A user has a rather large Excel spreadsheet that used to update links from other spreadsheets in the same directory. Now for some reason, it freezes whenever he tries to update links. I can open it and so can others, yet he always seems to freeze up. I’ve tried removing and reinstalling and patching Excel 2003 but nothing. I’m literally stuck…any other suggestions as to why it freezes up like this?