Outlook 2003 delay when opening e-mail

[Mr. Ian]

I have a user who experiences about a 10 second delay every time he
opens an e-mail in Outlook 2003. We are using Exchange server 2003
and no one else is experiencing this problem so I'm pretty sure it's
client side. When he opens an e-mail, there is heavy disk activity
for about 10 seconds before the e-mail will open. The computer has
1.5GB of memory so that shouldn't be the problem. Outlook is running
in cached mode, however other people with the same amount of e-mail
are not experiencing this issue. Are there any optimizations or
trouble shooting techniques I could use to improve performance?

Thanks