I have a Realtek 8191/8192SE wifi card embedded in my Medion Akoya S5612. As usual for Realtek, this card has only support for Windows. I had to use ndiswrapper to get the card working under Ubuntu 9.10. Steps:
download the Realtek 8192SE driver
from Synaptic, install the ndisgtk package (dependencies are automatically selected)
now, in System / Administration / Window Wireless Drivers you can install the windows driver. Select the Win2K driver.