I finally was able to get a Rosewill RNX-EasyN1 on a Suse 11.3 system, kernel 2.6.34. The drivers on the Rosewill site aren't appropriate anymore - the chipset in the currently shipped units is the RA3070. The driver is available from Ralinktech here:

Ralink Corp.Drivers

Choose the "RT8070/RT3070/RT3370 USB" driver. The file is called 2011_0107_RT3070_RT3370_Linux_STA_v2.5.0.1_DPO.tar.bz2. It's really a gzip file, so just change the file extention from .bz2 to .gz.

But there were some source modifications needed, which are described here:

rt3070sta: module license 'unspecified' taints kernel... SOLVED - Linux Forums

I don't believe that the copy of RT2870STA.dat to RT3070STA.dat is necessary. Anyway, after "modprobe ra3070sta", the 'ra0' device was created, and seemed to work just fine.

I'm not sure why Yast2 didn't pick up the device after installing the driver. It seems to want the device name to be "wlan0". I went through most of the motions, and then renamed the file 'ifcfg-wlan0' to 'ifcfg-ra0' in /etc/sysconfig/network.

Sure wish the manufacturers would supply working drivers with their product. It's a lot of effort to go through for a $20 device.