Word processors freeze when I paste into them

For a few months, now, when I paste something into Word 2003, the window hazes over and the program stops responding. Usually, it comes back to life after several minutes. I'd considered that a Word problem--but today, when I tried the same thing with OpenOffice, I got the same result. This only occurred with the first thing I pasted in, but the others were quite similar so it may have more to...