is wi capable to work in shared key mode?

Hello folks,

I have D-LINK DWL-900AP+ access point, and laptop with prism2-based wireless nic
onboard. My AP can be configured to use WEP in 'open mode' (e.g. allowing
both encrypted and unencrypted connections) and 'restricted
(shared key) mode' (e.g. allowing only encrypted connections).
My system is freebsd-current. Acording to ifconfig(8), wireless card can be
configured in restricted mode (mepmode on) and open mode (wepmode
mixed). The problem is 'wepmode on' works ONLY when AP is in Open
mode, but I want to allow only encrypted connections. But then I put
my AP into 'shared key' mode, freebsd losts its association with AP.
However, wireless nic is capable to work in restricted mode, because
in Linux 'iwconfig eth1 key [1] restricted' works fine.
I guess it's freebsd wi(4) issue, isn't it?