Unable to open database from shared folder in Excel VBA

I have an Excel spreadsheet originally developed in Excel 2000, in which
users enter data in their own workstation and click a button to transfer the
data to a centralized database. It works perfectly in Excel 2003, but have
problems in the new machines we bought (running Windows Vista Ultimate and
Office 2007). I got a run-time error saying that method 'OpenCurrentdatabase'
of object '_Application' failed.

It works if I moved the database to my local hard drive, so I suspect the
problem is about network and sharing of files in Windows Vista (I can see and
open the database from Windows Explorer). We have a peer-to-peer network with
a computer designated as a database server, running MS Windows 98 SE without
MS Office. The folder MASTER-DB is in full access with no password.

Dim appAccess As Variant
Dim dbCurrent As Variant

Set appAccess = CreateObject("Access.Application")
appAccess.Opencurrentdatabase "\\COMP 45 - NET S\MASTER-DB\Master.mdb"

Set dbCurrent = appAccess.CurrentDb
....

Any help would be greatly appreciated!!

Thanks,
Sarah