Check the connection string in web.config, it points to portal.mdb. In addition all data access files use System.Data.OleDB class.
I think portuga left all original IBuySpy files in case someone wanted to switch back to SQL server.
Well, I think by now you probably figured out how to make the app work 8-)
I made it work by simply copying the PortalVBVS folder to my wwwroot, created an IIS app., copied portal.mdb to the PortalVBVS folder, and changed connection string to point to folder where the db is. That's all.
Happy programming