Some e-mail messages...all words are underlined

[RoninTX]

- Windows XP with SP-2 (pbm existed prior to SP-2)
- IE 6.0.2800, SP-1 (pbm existed prior to SP-1)
- Office XP
- Outlook
- Problem : approx. 40-50% of e-mail messages arrive
with all words "underlined" (huge distraction".
- Going to "edit"..."change to HTML"..."edit" (to remove
underlining) solves the problem, but is a major pain.
- Other 50-60% of messages arrive without underlining.
- Any suggestions on what settings to change appreciated.