She'd be happy to phone me, I'm sure, but actually she's in the office next to mine! It was happening on Friday but, it seemed, only from one computer using only Word 2003 on a mail merged document.
It's one of those problems that's 'been happening for a long time' but is impossible to replicate when a tech has a look.
Thanks for the suggestions -
I'll look into the paper size - that sounds strangely familiar
Thanks everyone
(edit: found the advanced options on the print server and paper size was indeed 'letter') *crosses fingers*