OpenSUSE Wireless :: Unable To Set Up Ad-hoc Network

I'm using OpenSUSE 11.3 64-bit on a Lenovo G560. I'm able to establish both wired and unwired connections without problems. Now I'm in a situation where I'd like to share my laptop's internet connection with other devices. My thought was to establish an ad-hoc network that another computer could connect to wirelessly in order to get into the Internet, because I've only got one ethernet jack.

First thought was to use Network Manager, since that manages all my connections. A left click on the Network Manager icon brings up a menu in which "Wireless 802.11, Create network connection..." is an option. If I click on that I see a list of all the networks available in the area, as well as all the networks I've set up in the past. Below that are two options: "New Ad-Hoc Network" and "Connect To Other Network With Wireless 802.11..."

"New Ad-Hoc Network" seems like the right option, but when I double click on it the window closes and nothing happens. No error message, nothing. Network Manager continues to run and my connection is unchanged. If I just left click on it and then click "Connect" at the bottom of the window, the same thing happens.