Outlook Web Access and Outlook Express 5 on OS 9.2.2 attachments

[Raven]

Couldn't find an answer on the net as it brings up almost only unrelated results.
We use Exchange and have activated OWA. It works fine for most cases. However, one user has an issue where attachments sent via Outlook Express 5.0.2 in OS 9.2.2 to an exchange account, when the recipient checks his mail in OWA, all the attachments are in .hqx format, even though the Mac OS 9.2.2 guy sent them sinmply as jpeg, doc, ppt. The strange quirk is that is the recipient takes a look at the attachments in Outlook 2003 on Windows, he sees the attachments properly. Anyone has run across this issue ? (I'm pretty sure it falls under the "Stupid glitches in OWA section, but still I'd like to know if I'm alone or not in this.)