Why orinoco driver for pcmcia card with prism 2.5 chip?

[Ubu Roi]

I plugged a Senao 2511CD pcmcia wlan card with a prism 2.5 chip into
my warty laptop and it seems to be recognized 'out of the box'.

 (I can't check if it actually works because I am at home and have no
  access point handy).

However instead of the prism2 driver, which I expected, the orinoco
driver gets loaded. Why is this?

And if the orinoco driver is in some ways a better choice why is'nt
the 'patched' version available so kismet can be used without
'trials and tribulations'. Kismet is after all included in universe.

Ubu