adhoc with wpa_supplicant

[Sean]

I was able to get adhoc and wpa_supplicant 0.5.5 to work on a Via VT6655 
card using ndiswrapper. I am able to connect up 7 devices in an area, 
all pingable. I can get WPA-TKIP and WPA-AES working with WPA-NONE.

When I try the same settings on Atheros and Madwifi I only can connect 
two devices. The third device will not pass traffic.

I suspect that with ndiswrapper, wpa_supplicant is performing software 
encryption. With Atheros and madwifi, the hardware is doing the 
encryption. Am I correct on this?

Is there a way in wpa_supplicant to turn off hardware encryption? Or 
would this be more in the realm of the Madwifi driver?

Thanks in advance.

Sean