Word '03 documents printing with boxed fields

Hello,

In my company all users run Windows XP Professional, Service Pack 3.

I have a number of users who, when they print Word documents with pre-set fields, occassionally find that certain field groupings print out with a box-border around them and lines separating each line within. Thisdoes not show up on-screen or on the print preview and I cannot see any settings in the menu bar. The only thing you can see when you click on the various field groupings are a thick-lined grey box but this differs from the print out which has sharp lines and includes, as I mentioned, lines beneath each written line within the box.

When I print the document there are no boxes or lines(as it is meant to be).

The documents in question reside on a central company database and file management system.

Does anyone have any ideas why this might be happening?