I got this to work in this fashion.
Login as the admin user. click START | Run | and type in the name of your server in the run box (ie \\servername) press OK.
This will browse to the SME server, click on Printers and Faxes. Click on the shared printer you're trying to upload the drivers for. Right click and select properties. Click the advanced Tab. Next to the Driver dropdown is the New Driver button. Click that, select your driver and let it install to \\{servername}. Once thats done, press Apply, then OK. I also find it best to install the driver as a local printer on the admin windows account first before I install the driver on the \\{servername}\printers and faxes\{shared printer}. Can't say its a must but for those printer driver installs that do different things, it seems to put the drivers in the right spot so windows finds them automatically.