Assigning tun Interfaces?

[yanosz]

Hello,
I'm new to pfSense and I'm using 1.2.2. PfSense is works as OpenVPN Server / Gateway.
So far, everything is running fine, but I'ven't figured out how to assign tun-Interfaces yet.

I can assign tap interfaces (and push firewall rules for 'em) without any problem, but tun interfaces
don't appear within the interfaces drop-down list. (Tab: interfaces, sub-tab: assign) - The interfaces itself are up-an-runnig (Clients can connect and ifconfig (on shell) lists 'em)

Since some vista clients have trouble running tap, I'd prefere to use tun.
Is there a way to assign tun interfaces?

Thanks,
Keep smiling
yanosz