Outlook Automation

I have the following code:

Dim objOutlook as Object
set oOutlook = CreateObject("Outlook.Application")
...



On everyone's computer, this code works, but for some reason, on a particular user's computer (Win98 SE), the object cannot be created.
I am not putting the Outlook object library in the project's references because I am running this app on Win95, Win98, WinNT, Win2000. The computer that this app is not working, does have the msvbvm60.dll, msoutl8.olb and msoutl85.olb.
Any suggestions or help is greatly appreciated. Thanks.