Partial Receipt of Email Message

In Outlook 2000/Win98, I occasionally receive email from parties using newer versions (Outlook 2002). I periodically receive only a small section of a lengthy email when I first open it. I can then view the entire email when I reply to it. I havemy Outlook set up to receive in HTML format and use Word as email editor. Does this sound like incompatibility, or could there be a setting for min.-max. email size? This email did not contain any attachments and was approx. 28k in size.