Our computer has been having a bit of an 'attitude' lately, and it's really annoying!!

Have you tried the "detect and restore" option?? I haven't a clue exactly what that is, but after reading your post I looked at our Word, which is also 2003.

Go into Word, and click on "help" on the menu bar across the top...ours has a "detect and repair" option on the dropdown menu; when I clicked it, it said it will find and fix errors in all office files.