Outlook 2007 doesn't show entire message?

This has me puzzled so I wanted to see if anyone else already has the answer.

Outlook 2007 on Windows XP Pro SP3. Some emails received show the text from the sender but not the forwarded text. The email is in HTML but the text is still missing when viewed as plain text. This is true of Outlook 2007 and OWA 2003. I can see the missing text if I view the message in a browser. The way we found this issue is that the full text shows on the Blackberry attached to the account.

I've tried disabling the ESET add-in for Outlook and turning off the integration on the AV side. This didn't help.

anyone have more troubleshooting ideas?

Thanks!