Infrastructure vs Ad hoc

According to numerous resources on the web, infrastructure mode is the wireless networking framework in which devices communicate with each other by first going through an access point (such as the NetGear WGR614 wireless "router" I just acquired); compare this with ad-hoc mode, in which devices communicate directly with each other, without the use of an access point.

My notebook dual-boots Win98 and FreeBSD 4.10; the latter does not support the NetGear WG511, whereas FreeBSD 5.3 does. So it looks like it's time for me to upgrade my FreeBSD.

Meanwhile, the notebook is networking wirelessly using Win98. Since I have an access point, said notebook's wireless adapter is set to infrastructure mode.

The question is, while in infrastructure mode, what does it do when another adapter in the neighbourhood attempts to connect to it in ad-hoc mode? (If such a notion makes sense in the context of 802.11.)

Definitely need to upgrade FreeBSD and buy another wireless adapter...