Speaking only for myself I think Wicd is a load of horsepoop. Maybe it is something to do with that particular model of Alfa (I own it too) but it never works right for me. If I tell it to connect to network X it connects to network Y. It only discovers 1/2 the networks I can get in Windows 7, and it is slow as ice on any connection that is not at 100% line quality.
So the fact that you have problem with Wicd and Alfa is not surprising. And don't even bother going over to the Wicd forums because the developers are in denial that there is any problem whatsoever.
I guess what I am trying to say is I honestly don't think this is a BT4 problem. I think it's a Wicd problem. Or maybe it's a driver problem. Hell, I don't know; I'm not an expert on how all these intertwine. What can I say.
Welcome to the club????