Is this not related to the draconian fix as part of SP3 from O2K onwards?
Before you start using Office 2000 SP-3 seriously, you need to install a few utilities.
SP-3 includes the draconian email security update. Outlook 2000 with SP-3 installed takes it upon itself to hide certain files that are sent to you attached to email messages. As long as you have the discipline to avoid double-clicking on any files that come your way, Outlook's behaviour is supremely irritating. Fortunately, Ken Slovak's ATTOPT utility lets you take back control of which files Outlook blocks, and which it delivers to you. The utility's free, but Ken asks for a $10 donation to offset his expenses - money well spent, in my opinion. See
http://www.slovaktech.com/attachmentoptions.htm for details.