New wireless adapter = no return from standby?

Recently loaded a MS Broadband Network Wireless Notebook
Adapter (MN-520). The Wireless Base Station is another
computer in our home. Works like a dream. BUT ... my
laptop will NOT return from standby now. I hear it come
on, but get a black screen w/flashing cursor at the top
left. I have to restart via ctrl-alt-delete abobut 50 % of
the time ... the other 50% I have to unplug and remove the
battery, as neither the ctrl-alt-delete nor power key does
the job. That can't be good! Help!