Text boxes have black outline in rtf on some PCs only why?

[Darren]

I have some rtf files which have text boxes throughout. On some PCs running
MS Word 2003 the boxes appear with black outlines. On other PCs running the
same version of work they do not have outlines. I know I can change the
shape attributes one box at a time but this would be pain with lots of files
and we create more each day. Can anyone tell me why this happens and how to
get around the problem. What I really need not to have any lines appearing
around the text boxes.

Thanks for your help.